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Recent Red Hat Http Server Security Advisories

Advisory Title Published
RHSA-2026:56869 (RHSA-2026:56869) Important: Red Hat JBoss Core Services Apache HTTP Server 2.4.62 SP5 security update August 19, 2026
RHSA-2026:27200 (RHSA-2026:27200) Important: Red Hat JBoss Core Services Apache HTTP Server 2.4.62 SP4 security update June 22, 2026
RHSA-2026:27201 (RHSA-2026:27201) Important: Red Hat JBoss Core Services Apache HTTP Server 2.4.62 SP4 security update June 22, 2026
RHSA-2026:2995 (RHSA-2026:2995) Important: Red Hat JBoss Core Services Apache HTTP Server 2.4.62 SP3 security update February 23, 2026
RHSA-2026:2994 (RHSA-2026:2994) Important: Red Hat JBoss Core Services Apache HTTP Server 2.4.62 SP3 security update February 23, 2026
RHSA-2025:19020 (RHSA-2025:19020) Important: Red Hat JBoss Core Services Apache HTTP Server 2.4.62 SP2 security update October 27, 2025
RHSA-2025:13681 (RHSA-2025:13681) Important: Red Hat JBoss Core Services Apache HTTP Server 2.4.62 SP1 security update August 14, 2025
RHSA-2025:13680 (RHSA-2025:13680) Important: Red Hat JBoss Core Services Apache HTTP Server 2.4.62 SP1 security update August 14, 2025
RHSA-2025:3453 (RHSA-2025:3453) Important: Red Hat JBoss Core Services Apache HTTP Server 2.4.62 security update April 2, 2025
RHSA-2024:6928 (RHSA-2024:6928) Important: Red Hat JBoss Core Services Apache HTTP Server 2.4.57 SP6 security update September 24, 2024

By the Year

In 2026 there have been 41 vulnerabilities in Red Hat Http Server with an average score of 7.4 out of ten. Last year, in 2025 Http Server had 21 security vulnerabilities published. That is, 20 more vulnerabilities have already been reported in 2026 as compared to last year. However, the average CVE base score of the vulnerabilities in 2026 is greater by 0.13.

Year Vulnerabilities Average Score
2026 41 7.42
2025 21 7.30
2024 9 8.36

It may take a day or so for new Http Server vulnerabilities to show up in the stats or in the list of recent security vulnerabilities. Additionally vulnerabilities may be tagged under a different product or component name.

Recent Red Hat Http Server Security Vulnerabilities

libcurl SSH Key Type Mismatch Allows Silent MITM via CURLOPT_SSH_KEYFUNCTION
CVE-2026-9547 7.4 - High - July 03, 2026

When a libcurl-based application performs transfers via `SCP://` or `SFTP://` and utilizes the `CURLOPT_SSH_KEYFUNCTION` callback, it may silently accept an untrusted server. This vulnerability occurs when a server presents a host key type that does not match the specific key type already recorded for that host in the `known_hosts` file. Instead of rejecting the mismatch, the callback mechanism fails to properly enforce the restriction, allowing the connection to succeed without warning and risking a potential man-in-the-middle attack.

libcurl HTTP/3 session resumption EarlyData info leak
CVE-2026-9545 7.5 - High - July 03, 2026

In this scenario, libcurl first uses a proper HTTP/3 server for the initial transfers, and when it makes a second transfer to the same site it has been replaced by the attacker's impostor machine - without a valid certificate. When libcurl returns to the hostname the second time with a cached SSL session (`CURLOPT_SSL_SESSIONID_CACHE` is not disabled) and early data enabled (the `CURLSSLOPT_EARLYDATA` bit is set in `CURLOPT_SSL_OPTIONS`), libcurl might send off the second request's bytes on that new connection *before* enforcing the certificate verification failure. Potentially leaking sensitive information.

Privilege Esc Escalation: libcurl Fails to Clear Proxy Auth Credentials
CVE-2026-9079 9.8 - Critical - July 03, 2026

libcurl had a flaw that when instructed to clear proxy authentication credentials which made it not do so, leaving the old credentials around to get used for subsequent transfers that should not know nor use them.

libcurl mTLS cert mismatch causes insecure connection reuse
CVE-2026-8932 7.5 - High - July 03, 2026

libcurl would reuse a previously created connection even when some mTLS config related option had been changed that should have prohibited reuse. libcurl keeps previously used connections in a connection pool for subsequent transfers to reuse if one of them matches the setup. However, some TLS settings related to client certificates were left out from the configuration match checks, making them match too easily. In particular options related to the private key.

libcurl: Proxy Auth Leakage on Reused Handles
CVE-2026-8927 9.1 - Critical - July 03, 2026

When reusing a libcurl handle for sequential transfers driven by environment-variable proxy configuration, libcurl fails to clear the proxy authentication state between requests. Specifically, if the initial transfer authenticates against `proxyA` using Digest auth, a subsequent transfer routed through `proxyB` erroneously leaks the `Proxy-Authorization:` header intended solely for `proxyA`.

Curl Cookie Parsing Vulnerability: Super Cookies Bypass PSL
CVE-2026-8924 9.1 - Critical - July 03, 2026

A flaw in curls cookie parsing logic allows a malicious HTTP server to set 'super cookies' that bypass the Public Suffix List check. This enables an attacker-controlled origin to inject cookies that curl subsequently scopes and transmits to unrelated third-party domains.

libcurl Negotiate Authentication Connection Reuse Flaw
CVE-2026-8458 6.5 - Medium - July 03, 2026

libcurl might in some circumstances reuse the wrong connection when asked to do Negotiate-authenticated ones, even when they are set to use different 'services'. libcurl features a pool of recent connections so that subsequent requests can reuse an existing connection to avoid overhead. When reusing a connection a range of criteria must be met. Due to a logical error in the code, a request that was issued by an application could wrongfully reuse an existing connection to the same server that was authenticated using different services.

CURL STARTTLS Connection Reuse with TLS Mismatch
CVE-2026-8286 8.1 - High - July 03, 2026

A vulnerability exists where a new transfer that uses STARTTLS to upgrade the connection might reuse an existing live connection even though the TLS configuration mismatches so it should not.

cURL SSH Host Verification Bypass via Schemaless URL & --proto-default
CVE-2026-12064 7.5 - High - July 03, 2026

When a user invokes curl using a schemeless URL combined with `--proto-default` sftp (or scp), a disconnect occurs between the tool layer and libcurl. The tool layer incorrectly infers the URL scheme, which erroneously bypasses the initialization of critical SSH security options like CURLOPT_SSH_HOST_PUBLIC_KEY_SHA256 and CURLOPT_SSH_KNOWNHOSTS. Conversely, the libcurl runtime successfully honors CURLOPT_DEFAULT_PROTOCOL and establishes the connection via SFTP/SCP as specified. Because the tool layer skipped the security configuration, these SSH host verification options are silently omitted, causing curl to connect to an unverified SSH remote host without throwing an error.

Use-After-Free in libcurl during cleanup after stream-dependency reset
CVE-2026-10536 9.8 - Critical - July 03, 2026

A use-after-free vulnerability exists in libcurl when an application configures an HTTP/2 stream-dependency tree via `CURLOPT_STREAM_DEPENDS` or `CURLOPT_STREAM_DEPENDS_E`, subsequently invokes `curl_easy_reset()`, and finally terminates the handle with `curl_easy_cleanup()`. During this final cleanup phase, libcurl attempts to access and modify an internal structure that was already freed during the reset operation.

Apache HTTP Server mod_http DoS via Excessive Memory Allocation (2.4.17-2.4.67)
CVE-2026-49975 7.5 - High - June 08, 2026

Memory Allocation with Excessive Size Value vulnerability in Apache HTTP Server's mod_http leads to denial of service via malicious HTTP requests. This issue affects Apache HTTP Server: from 2.4.17 through 2.4.67.

Stack Exhaustion

Apache HTTP Server 2.4.55-2.4.67 Mod_http2 Use-After-Free Exhausted Handles
CVE-2026-48913 7.3 - High - June 08, 2026

Use After Free vulnerability in Apache HTTP Server module mod_http2 when file handles are already exhausted. This issue affects Apache HTTP Server: from 2.4.55 through 2.4.67.

Dangling pointer

Heap Overflow in mod_xml2enc of Apache HTTP Svr 2.4.02.4.672.4.68
CVE-2026-42536 7.5 - High - June 08, 2026

Heap-based Buffer Overflow vulnerability in Apache HTTP Server with mod_xml2enc, xml2StartParse, and untrusted content This issue affects Apache HTTP Server: from 2.4.0 through 2.4.67. Users are recommended to upgrade to version 2.4.68, which fixes the issue.

Heap-based Buffer Overflow

Apache HTTP Server 2.4.0-2.4.67 OCSP Outbound Buffer Over-read
CVE-2026-44185 7.3 - High - June 08, 2026

Buffer Over-read vulnerability in Apache HTTP Server via outbound OCSP requests to an attacker controlled OCSP server This issue affects Apache HTTP Server: from 2.4.0 through 2.4.67. Users are recommended to upgrade to version 2.4.68, which fixes the issue.

Buffer Over-read

Apache HTTP Server 2.4.67 mod_proxy_html Buffer Overflow CVE-2026-34355
CVE-2026-34355 7.5 - High - June 08, 2026

A buffer overflow in mod_proxy_html in Apache HTTP Server 2.4.67 and earlier allows an attack by an untrusted backend. Users are recommended to upgrade to version 2.4.68, which fixes this issue.

Heap-based Buffer Overflow

Apache HTTP Server 2.4.0-2.4.67 Buffer Underwrite via Regex
CVE-2026-44631 9.8 - Critical - June 08, 2026

Buffer Underwrite vulnerability in Apache HTTP Server on crafted regular expressions in the configuration. This issue affects Apache HTTP Server: from 2.4.0 through 2.4.67. Users are recommended to upgrade to version 2.4.68, which fixes the issue.

buffer underrun

Apache HTTP Server 2.4.67 Improper Privilege Mng in .htaccess (Fixed 2.4.68)
CVE-2026-44119 5.5 - Medium - June 08, 2026

Improper Privilege Management vulnerability in Apache HTTP Server 2.4.67 and earlier allows local .htaccess authors to read files with the privileges of the httpd user. This issue affects Apache HTTP Server: from through 2.4.67. Users are recommended to upgrade to version 2.4.68, which fixes the issue.

Improper Privilege Management

Apache HTTP Server <= 2.4.67: OOB Read in mod_headers/mod_mime
CVE-2026-43951 6.5 - Medium - June 08, 2026

Out-of-bounds Read vulnerability in Apache HTTP Server with mod_headers and mod_mime and multiple response languages. This issue affects Apache HTTP Server: from 2.4.0 through 2.4.67.

Out-of-bounds Read

Apache 2.4.68 - Path Handling Vulnerability in mod_dav_fs (CVE-2026-42535)
CVE-2026-42535 9.1 - Critical - June 08, 2026

A path handling issue in mod_dav_fs in Apache 2.4.67 and earlier allows a WebDAV content author to directly manipulate trusted DAV property databases, potentially causing child process crashes. Users are recommended to upgrade to version 2.4.68, which fixes this issue.

Exposure of Resource to Wrong Sphere

Apache HTTP 2.4.x mod_proxy_ftp Infinite Loop (before 2.4.68)
CVE-2026-44186 7.3 - High - June 08, 2026

Loop with Unreachable Exit Condition ('Infinite Loop') vulnerability in the mod_proxy_ftp module in Apache HTTP Server with an attacker controlled backend FTP server. This issue affects undefined: from 2.4.0 through 2.4.67. Users are recommended to upgrade to version 2.4.68, which fixes the issue.

Infinite Loop

Apache HTTP Server 2.4.67 XSS in mod_proxy_ftp Dir List Generation
CVE-2026-29170 6.1 - Medium - June 08, 2026

A cross-site scripting vulnerability exists in mod_proxy_ftp's HTML directory list generation in Apache HTTP Server 2.4.67 and earlier when listing FTP directory contents either via forward or reverse proxy configuration. Users are recommended to upgrade to version 2.4.68, which fixes this issue.

XSS

Apache HTTP 2.4.02.4.67 Use-After-Free mod_ldap (per-dir) fixed in 2.4.68
CVE-2026-29167 9.8 - Critical - June 08, 2026

Use After Free vulnerability in Apache HTTP Server with mod_ldap in per-directory configuration This issue affects Apache HTTP Server: from 2.4.0 through 2.4.67. Users are recommended to upgrade to version 2.4.68, which fixes the issue.

Dangling pointer

libcurl Proxy Digest Auth Header Leak on Handle Reuse
CVE-2026-7168 5.3 - Medium - May 13, 2026

Successfully using libcurl to do a transfer over a specific HTTP proxy (`proxyA`) with **Digest** authentication and then changing the proxy host to a second one (`proxyB`) for a second transfer, reusing the same handle, makes libcurl wrongly pass on the `Proxy-Authorization:` header field meant for `proxyA`, to `proxyB`.

Curl Credential Leak via Proxy Chain Redirect
CVE-2026-6253 5.9 - Medium - May 13, 2026

curl might erroneously pass on credentials for a first proxy to a second proxy. This can happen when the following conditions are true: 1. curl is setup to use specific different proxies for different URL schemes 2. the first proxy needs credentials 3. the second proxy uses no credentials 4. while using the first proxy (using say `http://`), curl is asked to follow a redirect to a URL using another scheme (say `https://`), accessed using a second, different, proxy

Denial of Service via Attribute Name Collision in libexpat < 2.8.1
CVE-2026-45186 7.5 - High - May 10, 2026

In libexpat before 2.8.1, the computational complexity of attribute name collision checks allows a denial of service via moderately sized crafted XML input.

Inefficient Algorithmic Complexity

Apache HTTP Server 2.4.66 mod_proxy_ajp Heap Buffer Overflow (CVE-2026-28780)
CVE-2026-28780 8.1 - High - May 05, 2026

Heap-based Buffer Overflow vulnerability in mod_proxy_ajp of Apache HTTP Server. If mod_proxy_ajp connects to a malicious AJP server this AJP server can send a malicious AJP message back to mod_proxy_ajp and cause it to write 4 attacker controlled bytes after the end of a heap based buffer. This issue affects Apache HTTP Server: through 2.4.66. Users are recommended to upgrade to version 2.4.67, which fixes the issue.

Heap-based Buffer Overflow

Apache HTTP Server 2.4.30-2.4.66 mod_md OCSP Resource Exhaustion Vulnerability
CVE-2026-29168 7.3 - High - May 05, 2026

Allocation of Resources Without Limits or Throttling vulnerability in Apache HTTP Server's  mod_md via OCSP response data. This issue affects Apache HTTP Server: from 2.4.30 through 2.4.66. Users are recommended to upgrade to version 2.4.67, which fixes the issue.

Allocation of Resources Without Limits or Throttling

Apache HTTP Server 2.4.66 mod_dav_lock Null PTR Crash
CVE-2026-29169 7.5 - High - May 04, 2026

A NULL pointer dereference in mod_dav_lock in Apache HTTP Server 2.4.66 and earlier may allow an attacker to crash the server with a malicious request.mod_dav_lock is not used internally by mod_dav or mod_dav_fs. The only known use-case for mod_dav_lock was mod_dav_svn from Apache Subversion earlier than version 1.2.0. Users are recommended to upgrade to version 2.4.66, which fixes this issue, or remove mod_dav_lock.

NULL Pointer Dereference

Apache HTTP Server 2.4.66: mod_authn_socache NULL deref crash (before 2.4.67)
CVE-2026-33007 5.3 - Medium - May 04, 2026

A NULL pointer dereference in the mod_authn_socache in Apache HTTP Server 2.4.66 and earlier allows an unauthenticated remote user to crash a child process in a caching forward proxy configuration. Users are recommended to upgrade to version 2.4.67, which fixes this issue.

NULL Pointer Dereference

Apache HTTP Server 2.4.66: OOB Read in mod_proxy_ajp (fixed 2.4.67)
CVE-2026-33857 5.3 - Medium - May 04, 2026

Out-of-bounds Read vulnerability in mod_proxy_ajp of Apache HTTP Server. This issue affects Apache HTTP Server: through 2.4.66. Users are recommended to upgrade to version 2.4.67, which fixes the issue.

Out-of-bounds Read

Apache HTTP Server <=2.4.66 Null-Termination OOB Read
CVE-2026-34032 5.3 - Medium - May 04, 2026

Improper Null Termination, Out-of-bounds Read vulnerability in Apache HTTP Server. This issue affects Apache HTTP Server: through 2.4.66. Users are recommended to upgrade to version 2.4.67, which fixes the issue.

Improper Null Termination

Apache HTTP Server 2.4.66 Buffer Over-Read Vulnerability
CVE-2026-34059 7.5 - High - May 04, 2026

Buffer Over-read vulnerability in Apache HTTP Server. This issue affects Apache HTTP Server: through 2.4.66. Users are recommended to upgrade to version 2.4.67, which fixes the issue.

Buffer Over-read

CVE-2026-24072: Apache HTTPD 2.4.66-2.4.67 Priv Escalation via .htaccess
CVE-2026-24072 8.8 - High - May 04, 2026

An escalation of privilege bug in various modules in Apache HTTP 2.4.66 and earlier allows local .htaccess authors to read files with the privileges of the httpd user. Users are recommended to upgrade to version 2.4.67, which fixes this issue.

Improper Privilege Management

OpenSSL 3.6+ RSA KEM Buffer Leak via EVP_PKEY_encapsulate
CVE-2026-31790 7.5 - High - April 07, 2026

Issue summary: Applications using RSASVE key encapsulation to establish a secret encryption key can send contents of an uninitialized memory buffer to a malicious peer. Impact summary: The uninitialized buffer might contain sensitive data from the previous execution of the application process which leads to sensitive data leakage to an attacker. RSA_public_encrypt() returns the number of bytes written on success and -1 on error. The affected code tests only whether the return value is non-zero. As a result, if RSA encryption fails, encapsulation can still return success to the caller, set the output lengths, and leave the caller to use the contents of the ciphertext buffer as if a valid KEM ciphertext had been produced. If applications use EVP_PKEY_encapsulate() with RSA/RSASVE on an attacker-supplied invalid RSA public key without first validating that key, then this may cause stale or uninitialized contents of the caller-provided ciphertext buffer to be disclosed to the attacker in place of the KEM ciphertext. As a workaround calling EVP_PKEY_public_check() or EVP_PKEY_public_check_quick() before EVP_PKEY_encapsulate() will mitigate the issue. The FIPS modules in 3.6, 3.5, 3.4, 3.3, 3.1 and 3.0 are affected by this issue.

Improper Check for Unusual or Exceptional Conditions

nghttp21.68.1: assertion fail via FRAME_SIZE_ERROR after session termination
CVE-2026-27135 7.5 - High - March 18, 2026

nghttp2 is an implementation of the Hypertext Transfer Protocol version 2 in C. Prior to version 1.68.1, the nghttp2 library stops reading the incoming data when user facing public API `nghttp2_session_terminate_session` or `nghttp2_session_terminate_session2` is called by the application. They might be called internally by the library when it detects the situation that is subject to connection error. Due to the missing internal state validation, the library keeps reading the rest of the data after one of those APIs is called. Then receiving a malformed frame that causes FRAME_SIZE_ERROR causes assertion failure. nghttp2 v1.68.1 adds missing state validation to avoid assertion failure. No known workarounds are available.

assertion failure

OpenSSL 3.5/3.6 TLS 1.3 Preferred KEX Tuple Bug (CVE-2026-2673)
CVE-2026-2673 6.5 - Medium - March 13, 2026

Issue summary: An OpenSSL TLS 1.3 server may fail to negotiate the expected preferred key exchange group when its key exchange group configuration includes the default by using the 'DEFAULT' keyword. Impact summary: A less preferred key exchange may be used even when a more preferred group is supported by both client and server, if the group was not included among the client's initial predicated keyshares. This will sometimes be the case with the new hybrid post-quantum groups, if the client chooses to defer their use until specifically requested by the server. If an OpenSSL TLS 1.3 server's configuration uses the 'DEFAULT' keyword to interpolate the built-in default group list into its own configuration, perhaps adding or removing specific elements, then an implementation defect causes the 'DEFAULT' list to lose its 'tuple' structure, and all server-supported groups were treated as a single sufficiently secure 'tuple', with the server not sending a Hello Retry Request (HRR) even when a group in a more preferred tuple was mutually supported. As a result, the client and server might fail to negotiate a mutually supported post-quantum key agreement group, such as 'X25519MLKEM768', if the client's configuration results in only 'classical' groups (such as 'X25519' being the only ones in the client's initial keyshare prediction). OpenSSL 3.5 and later support a new syntax for selecting the most preferred TLS 1.3 key agreement group on TLS servers. The old syntax had a single 'flat' list of groups, and treated all the supported groups as sufficiently secure. If any of the keyshares predicted by the client were supported by the server the most preferred among these was selected, even if other groups supported by the client, but not included in the list of predicted keyshares would have been more preferred, if included. The new syntax partitions the groups into distinct 'tuples' of roughly equivalent security. Within each tuple the most preferred group included among the client's predicted keyshares is chosen, but if the client supports a group from a more preferred tuple, but did not predict any corresponding keyshares, the server will ask the client to retry the ClientHello (by issuing a Hello Retry Request or HRR) with the most preferred mutually supported group. The above works as expected when the server's configuration uses the built-in default group list, or explicitly defines its own list by directly defining the various desired groups and group 'tuples'. No OpenSSL FIPS modules are affected by this issue, the code in question lies outside the FIPS boundary. OpenSSL 3.6 and 3.5 are vulnerable to this issue. OpenSSL 3.6 users should upgrade to OpenSSL 3.6.2 once it is released. OpenSSL 3.5 users should upgrade to OpenSSL 3.5.6 once it is released. OpenSSL 3.4, 3.3, 3.0, 1.0.2 and 1.1.1 are not affected by this issue.

Algorithm Downgrade

CURL: Improper HTTP Proxy Connection Reuse with Different Credentials
CVE-2026-3784 6.5 - Medium - March 11, 2026

curl would wrongly reuse an existing HTTP proxy connection doing CONNECT to a server, even if the new request uses different credentials for the HTTP proxy. The proper behavior is to create or use a separate connection.

Authentication Bypass by Primary Weakness

curl HTTP Redirect Leaks OAuth2 Bearer Token
CVE-2026-3783 5.3 - Medium - March 11, 2026

When an OAuth2 bearer token is used for an HTTP(S) transfer, and that transfer performs a redirect to a second URL, curl could leak that token to the second hostname under some circumstances. If the hostname that the first request is redirected to has information in the used .netrc file, with either of the `machine` or `default` keywords, curl would pass on the bearer token set for the first host also to the second one.

Insufficiently Protected Credentials

libcurl Negotiate Auth Reuse Vulnerability: Wrong Credential Leak
CVE-2026-1965 6.5 - Medium - March 11, 2026

libcurl can in some circumstances reuse the wrong connection when asked to do an Negotiate-authenticated HTTP or HTTPS request. libcurl features a pool of recent connections so that subsequent requests can reuse an existing connection to avoid overhead. When reusing a connection a range of criterion must first be met. Due to a logical error in the code, a request that was issued by an application could wrongfully reuse an existing connection to the same server that was authenticated using different credentials. One underlying reason being that Negotiate sometimes authenticates *connections* and not *requests*, contrary to how HTTP is designed to work. An application that allows Negotiate authentication to a server (that responds wanting Negotiate) with `user1:password1` and then does another operation to the same server also using Negotiate but with `user2:password2` (while the previous connection is still alive) - the second request wrongly reused the same connection and since it then sees that the Negotiate negotiation is already made, it just sends the request over that connection thinking it uses the user2 credentials when it is in fact still using the connection authenticated for user1... The set of authentication methods to use is set with `CURLOPT_HTTPAUTH`. Applications can disable libcurl's reuse of connections and thus mitigate this problem, by using one of the following libcurl options to alter how connections are or are not reused: `CURLOPT_FRESH_CONNECT`, `CURLOPT_MAXCONNECTS` and `CURLMOPT_MAX_HOST_CONNECTIONS` (if using the curl_multi API).

Authentication Bypass by Primary Weakness

OpenSSL OOB Write in PKCS12_get_friendlyname() 1.1.13.6
CVE-2025-69419 7.4 - High - January 27, 2026

Issue summary: Calling PKCS12_get_friendlyname() function on a maliciously crafted PKCS#12 file with a BMPString (UTF-16BE) friendly name containing non-ASCII BMP code point can trigger a one byte write before the allocated buffer. Impact summary: The out-of-bounds write can cause a memory corruption which can have various consequences including a Denial of Service. The OPENSSL_uni2utf8() function performs a two-pass conversion of a PKCS#12 BMPString (UTF-16BE) to UTF-8. In the second pass, when emitting UTF-8 bytes, the helper function bmp_to_utf8() incorrectly forwards the remaining UTF-16 source byte count as the destination buffer capacity to UTF8_putc(). For BMP code points above U+07FF, UTF-8 requires three bytes, but the forwarded capacity can be just two bytes. UTF8_putc() then returns -1, and this negative value is added to the output length without validation, causing the length to become negative. The subsequent trailing NUL byte is then written at a negative offset, causing write outside of heap allocated buffer. The vulnerability is reachable via the public PKCS12_get_friendlyname() API when parsing attacker-controlled PKCS#12 files. While PKCS12_parse() uses a different code path that avoids this issue, PKCS12_get_friendlyname() directly invokes the vulnerable function. Exploitation requires an attacker to provide a malicious PKCS#12 file to be parsed by the application and the attacker can just trigger a one zero byte write before the allocated buffer. For that reason the issue was assessed as Low severity according to our Security Policy. The FIPS modules in 3.6, 3.5, 3.4, 3.3 and 3.0 are not affected by this issue, as the PKCS#12 implementation is outside the OpenSSL FIPS module boundary. OpenSSL 3.6, 3.5, 3.4, 3.3, 3.0 and 1.1.1 are vulnerable to this issue. OpenSSL 1.0.2 is not affected by this issue.

Memory Corruption

OpenSSL 3.x CMS AuthEnvelopedData AEAD IV stack overflow (v3.6+)
CVE-2025-15467 9.8 - Critical - January 27, 2026

Issue summary: Parsing CMS AuthEnvelopedData or EnvelopedData message with maliciously crafted AEAD parameters can trigger a stack buffer overflow. Impact summary: A stack buffer overflow may lead to a crash, causing Denial of Service, or potentially remote code execution. When parsing CMS (Auth)EnvelopedData structures that use AEAD ciphers such as AES-GCM, the IV (Initialization Vector) encoded in the ASN.1 parameters is copied into a fixed-size stack buffer without verifying that its length fits the destination. An attacker can supply a crafted CMS message with an oversized IV, causing a stack-based out-of-bounds write before any authentication or tag verification occurs. Applications and services that parse untrusted CMS or PKCS#7 content using AEAD ciphers (e.g., S/MIME (Auth)EnvelopedData with AES-GCM) are vulnerable. Because the overflow occurs prior to authentication, no valid key material is required to trigger it. While exploitability to remote code execution depends on platform and toolchain mitigations, the stack-based write primitive represents a severe risk. The FIPS modules in 3.6, 3.5, 3.4, 3.3 and 3.0 are not affected by this issue, as the CMS implementation is outside the OpenSSL FIPS module boundary. OpenSSL 3.6, 3.5, 3.4, 3.3 and 3.0 are vulnerable to this issue. OpenSSL 1.1.1 and 1.0.2 are not affected by this issue.

Memory Corruption

Apache HTTP Server <2.4.66: SSI Exec Cmd Shell Injection via mod_cgid
CVE-2025-58098 8.3 - High - December 05, 2025

Apache HTTP Server 2.4.65 and earlier with Server Side Includes (SSI) enabled and mod_cgid (but not mod_cgi) passes the shell-escaped query string to #exec cmd="..." directives. This issue affects Apache HTTP Server before 2.4.66. Users are recommended to upgrade to version 2.4.66, which fixes the issue.

Insertion of Sensitive Information Into Sent Data

Apache HTTP Server 2.4.765 AllowOverride FileInfo Bypass
CVE-2025-66200 5.4 - Medium - December 05, 2025

mod_userdir+suexec bypass via AllowOverride FileInfo vulnerability in Apache HTTP Server. Users with access to use the RequestHeader directive in htaccess can cause some CGI scripts to run under an unexpected userid. This issue affects Apache HTTP Server: from 2.4.7 through 2.4.65. Users are recommended to upgrade to version 2.4.66, which fixes the issue.

Authentication Bypass Using an Alternate Path or Channel

Apache HTTP Server 2.4.02.4.65 ENV Var XSS via config, fixed in 2.4.66
CVE-2025-65082 6.5 - Medium - December 05, 2025

Improper Neutralization of Escape, Meta, or Control Sequences vulnerability in Apache HTTP Server through environment variables set via the Apache configuration unexpectedly superseding variables calculated by the server for CGI programs. This issue affects Apache HTTP Server from 2.4.0 through 2.4.65. Users are recommended to upgrade to version 2.4.66 which fixes the issue.

Improper Neutralization of Escape, Meta, or Control Sequences

Apache HTTPd 2.4.30-2.4.65 Integer Overflow in ACME Renewal Zero Backoff Timer
CVE-2025-55753 7.5 - High - December 05, 2025

An integer overflow in the case of failed ACME certificate renewal leads, after a number of failures (~30 days in default configurations), to the backoff timer becoming 0. Attempts to renew the certificate then are repeated without delays until it succeeds. This issue affects Apache HTTP Server: from 2.4.30 before 2.4.66. Users are recommended to upgrade to version 2.4.66, which fixes the issue.

Integer Overflow or Wraparound

OpenSSL CMS OOB Read/Write via PWRI Encr. (v<3.5)
CVE-2025-9230 7.5 - High - September 30, 2025

Issue summary: An application trying to decrypt CMS messages encrypted using password based encryption can trigger an out-of-bounds read and write. Impact summary: This out-of-bounds read may trigger a crash which leads to Denial of Service for an application. The out-of-bounds write can cause a memory corruption which can have various consequences including a Denial of Service or Execution of attacker-supplied code. Although the consequences of a successful exploit of this vulnerability could be severe, the probability that the attacker would be able to perform it is low. Besides, password based (PWRI) encryption support in CMS messages is very rarely used. For that reason the issue was assessed as Moderate severity according to our Security Policy. The FIPS modules in 3.5, 3.4, 3.3, 3.2, 3.1 and 3.0 are not affected by this issue, as the CMS implementation is outside the OpenSSL FIPS module boundary.

Out-of-bounds Read

Large Allocations in Expat <2.7.2 via Small XML (DoS)
CVE-2025-59375 7.5 - High - September 15, 2025

libexpat in Expat before 2.7.2 allows attackers to trigger large dynamic memory allocations via a small document that is submitted for parsing.

Allocation of Resources Without Limits or Throttling

Apache HTTP Server 2.4.x: mod_proxy_http2 assertion triggers DoS via proxy
CVE-2025-49630 7.5 - High - July 10, 2025

In certain proxy configurations, a denial of service attack against Apache HTTP Server versions 2.4.26 through to 2.4.63 can be triggered by untrusted clients causing an assertion in mod_proxy_http2. Configurations affected are a reverse proxy is configured for an HTTP/2 backend, with ProxyPreserveHost set to "on".

assertion failure

Apache HTTP Server 2.4.63 & earlier mod_ssl: HTTP Desync via TLS Upgrade
CVE-2025-49812 7.4 - High - July 10, 2025

In some mod_ssl configurations on Apache HTTP Server versions through to 2.4.63, an HTTP desynchronisation attack allows a man-in-the-middle attacker to hijack an HTTP session via a TLS upgrade. Only configurations using "SSLEngine optional" to enable TLS upgrades are affected. Users are recommended to upgrade to version 2.4.64, which removes support for TLS upgrade.

authentification

Apache Httpd 2.4.35-2.4.63 mod_ssl TLS1.3 SR Access Ctrl Bypass
CVE-2025-23048 9.1 - Critical - July 10, 2025

In some mod_ssl configurations on Apache HTTP Server 2.4.35 through to 2.4.63, an access control bypass by trusted clients is possible using TLS 1.3 session resumption. Configurations are affected when mod_ssl is configured for multiple virtual hosts, with each restricted to a different set of trusted client certificates (for example with a different SSLCACertificateFile/Path setting). In such a case, a client trusted to access one virtual host may be able to access another virtual host, if SSLStrictSNIVHostCheck is not enabled in either virtual host.

Authorization

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