GoLang Go

Go html/template XSS via meta content URL unescape <1.25.8, 1.26.0
CVE-2026-27142 7.5 - High - March 06, 2026

Actions which insert URLs into the content attribute of HTML meta tags are not escaped. This can allow XSS if the meta tag also has an http-equiv attribute with the value "refresh". A new GODEBUG setting has been added, htmlmetacontenturlescape, which can be used to disable escaping URLs in actions in the meta content attribute which follow "url=" by setting htmlmetacontenturlescape=0.

go stdlib: os ReadDir/FileInfo path escape before 1.25.8 & 1.26.1
CVE-2026-27139 2.5 - Low - March 06, 2026

On Unix platforms, when listing the contents of a directory using File.ReadDir or File.Readdir the returned FileInfo could reference a file outside of the Root in which the File was opened. The impact of this escape is limited to reading metadata provided by lstat from arbitrary locations on the filesystem without permitting reading or writing files outside the root.

CVE2025-68121: Go TLS Session Resumption with Mutated ClientCAs/RootCAs
CVE-2025-68121 4.8 - Medium - February 05, 2026

During session resumption in crypto/tls, if the underlying Config has its ClientCAs or RootCAs fields mutated between the initial handshake and the resumed handshake, the resumed handshake may succeed when it should have failed. This may happen when a user calls Config.Clone and mutates the returned Config, or uses Config.GetConfigForClient. This can cause a client to resume a session with a server that it would not have resumed with during the initial handshake, or cause a server to resume a session with a client that it would not have resumed with during the initial handshake.

Improper Certificate Validation

Go cgo Comment Parsing Discrepancy Enables Code Smuggling
CVE-2025-61732 8.6 - High - February 05, 2026

A discrepancy between how Go and C/C++ comments were parsed allowed for code smuggling into the resulting cgo binary.

Code Injection

TLS 1.3 Info Disclosure in Go TLS Library (Pre 1.22)
CVE-2025-61730 5.3 - Medium - January 28, 2026

During the TLS 1.3 handshake if multiple messages are sent in records that span encryption level boundaries (for instance the Client Hello and Encrypted Extensions messages), the subsequent messages may be processed before the encryption level changes. This can cause some minor information disclosure if a network-local attacker can inject messages during the handshake.

Go cmd/go <1.25.6 Local Code Exec via Malicious Version Strings in VCS Modules
CVE-2025-68119 7 - High - January 28, 2026

Downloading and building modules with malicious version strings can cause local code execution. On systems with Mercurial (hg) installed, downloading modules from non-standard sources (e.g., custom domains) can cause unexpected code execution due to how external VCS commands are constructed. This issue can also be triggered by providing a malicious version string to the toolchain. On systems with Git installed, downloading and building modules with malicious version strings can allow an attacker to write to arbitrary files on the filesystem. This can only be triggered by explicitly providing the malicious version strings to the toolchain and does not affect usage of @latest or bare module paths.

URL Parse Allows NonIPv6 in Brackets Host Validation Flaw
CVE-2025-47912 5.3 - Medium - October 29, 2025

The Parse function permits values other than IPv6 addresses to be included in square brackets within the host component of a URL. RFC 3986 permits IPv6 addresses to be included within the host component, enclosed within square brackets. For example: "http://[::1]/". IPv4 addresses and hostnames must not appear within square brackets. Parse did not enforce this requirement.

Go TLS Conn.Handshake leaks attackersupplied ALPN data
CVE-2025-58189 5.3 - Medium - October 29, 2025

When Conn.Handshake fails during ALPN negotiation the error contains attacker controlled information (the ALPN protocols sent by the client) which is not escaped.

Go LookPath PATH bug returns execs for empty/.. input
CVE-2025-47906 6.5 - Medium - September 18, 2025

If the PATH environment variable contains paths which are executables (rather than just directories), passing certain strings to LookPath ("", ".", and ".."), can result in the binaries listed in the PATH being unexpectedly returned.

Go database/sql Scan context cancellation race condition
CVE-2025-47907 7 - High - August 07, 2025

Cancelling a query (e.g. by cancelling the context passed to one of the query methods) during a call to the Scan method of the returned Rows can result in unexpected results if other queries are being made in parallel. This can result in a race condition that may overwrite the expected results with those of another query, causing the call to Scan to return either unexpected results from the other query or an error.

Go Tool Command Exe via Untrusted VCS Repository Config
CVE-2025-4674 8.6 - High - July 29, 2025

The go command may execute unexpected commands when operating in untrusted VCS repositories. This occurs when possibly dangerous VCS configuration is present in repositories. This can happen when a repository was fetched via one VCS (e.g. Git), but contains metadata for another VCS (e.g. Mercurial). Modules which are retrieved using the go command line, i.e. via "go get", are not affected.

External Control of File Name or Path

Go StdLib OpenFile O_CREATE/O_EXCL Symlink Handling Fix
CVE-2025-0913 - June 11, 2025

os.OpenFile(path, os.O_CREATE|O_EXCL) behaved differently on Unix and Windows systems when the target path was a dangling symlink. On Unix systems, OpenFile with O_CREATE and O_EXCL flags never follows symlinks. On Windows, when the target path was a symlink to a nonexistent location, OpenFile would create a file in that location. OpenFile now always returns an error when the O_CREATE and O_EXCL flags are both set and the target path is a symlink.

insecure temporary file

Go Cert Policy Validation Bypass via VerifyOptions with ExtKeyUsageAny
CVE-2025-22874 - June 11, 2025

Calling Verify with a VerifyOptions.KeyUsages that contains ExtKeyUsageAny unintentionally disabledpolicy validation. This only affected certificate chains which contain policy graphs, which are rather uncommon.

Arbitrary code exec via CGO LDFLAGS in Go1.24rc2 (Apple ld)
CVE-2025-22867 - February 06, 2025

On Darwin, building a Go module which contains CGO can trigger arbitrary code execution when using the Apple version of ld, due to usage of the @executable_path, @loader_path, or @rpath special values in a "#cgo LDFLAGS" directive. This issue only affected go1.24rc2.

Go ParsePKCS1PrivateKey Panic on Missing CRT
CVE-2025-22865 - January 28, 2025

Using ParsePKCS1PrivateKey to parse a RSA key that is missing the CRT values would panic when verifying that the key is well formed.

Go Parse Function Stack Exhaustion via Deeply Nested Literals
CVE-2024-34155 - September 06, 2024

Calling any of the Parse functions on Go source code which contains deeply nested literals can cause a panic due to stack exhaustion.

GO Compiler Parse Panic: Stack Exhaustion via Deeply Nested //+build tags
CVE-2024-34158 - September 06, 2024

Calling Parse on a "// +build" build tag line with deeply nested expressions can cause a panic due to stack exhaustion.

Go net/http Expect:100-continue mishandling before 1.20.7 leads to DDoS
CVE-2024-24791 - July 02, 2024

The net/http HTTP/1.1 client mishandled the case where a server responds to a request with an "Expect: 100-continue" header with a non-informational (200 or higher) status. This mishandling could leave a client connection in an invalid state, where the next request sent on the connection will fail. An attacker sending a request to a net/http/httputil.ReverseProxy proxy can exploit this mishandling to cause a denial of service by sending "Expect: 100-continue" requests which elicit a non-informational response from the backend. Each such request leaves the proxy with an invalid connection, and causes one subsequent request using that connection to fail.

Go net: IsPrivate/IsLoopback fail on IPv4-mapped IPv6 addresses
CVE-2024-24790 9.8 - Critical - June 05, 2024

The various Is methods (IsPrivate, IsLoopback, etc) did not work as expected for IPv4-mapped IPv6 addresses, returning false for addresses which would return true in their traditional IPv4 forms.

Go archive/zip Improper Handling of Invalid ZIP Files (CVE-2024-24789)
CVE-2024-24789 5.5 - Medium - June 05, 2024

The archive/zip package's handling of certain types of invalid zip files differs from the behavior of most zip implementations. This misalignment could be exploited to create an zip file with contents that vary depending on the implementation reading the file. The archive/zip package now rejects files containing these errors.

CVE-2024-3566: CreateProcessBased Command Injection in Windows Apps
CVE-2024-3566 9.8 - Critical - April 10, 2024

A command inject vulnerability allows an attacker to perform command injection on Windows applications that indirectly depend on the CreateProcess function when the specific conditions are satisfied.

Go net/http ParseMultipartForm Mem Exhaustion using Long Form Lines
CVE-2023-45290 - March 05, 2024

When parsing a multipart form (either explicitly with Request.ParseMultipartForm or implicitly with Request.FormValue, Request.PostFormValue, or Request.FormFile), limits on the total size of the parsed form were not applied to the memory consumed while reading a single form line. This permits a maliciously crafted input containing very long lines to cause allocation of arbitrarily large amounts of memory, potentially leading to memory exhaustion. With fix, the ParseMultipartForm function now correctly limits the maximum size of form lines.

Go Modules .git Suffix Causes Insecure git:// Fallback
CVE-2023-45285 7.5 - High - December 06, 2023

Using go get to fetch a module with the ".git" suffix may unexpectedly fallback to the insecure "git://" protocol if the module is unavailable via the secure "https://" and "git+ssh://" protocols, even if GOINSECURE is not set for said module. This only affects users who are not using the module proxy and are fetching modules directly (i.e. GOPROXY=off).

Go net/http Chunked Reader Vulnerability: HTTP Chunk Extension Overread
CVE-2023-39326 5.3 - Medium - December 06, 2023

A malicious HTTP sender can use chunk extensions to cause a receiver reading from a request or response body to read many more bytes from the network than are in the body. A malicious HTTP client can further exploit this to cause a server to automatically read a large amount of data (up to about 1GiB) when a handler fails to read the entire body of a request. Chunk extensions are a little-used HTTP feature which permit including additional metadata in a request or response body sent using the chunked encoding. The net/http chunked encoding reader discards this metadata. A sender can exploit this by inserting a large metadata segment with each byte transferred. The chunk reader now produces an error if the ratio of real body to encoded bytes grows too small.

Go TLS RSA Timing SideChannel vulnerability before 1.20
CVE-2023-45287 7.5 - High - December 05, 2023

Before Go 1.20, the RSA based TLS key exchanges used the math/big library, which is not constant time. RSA blinding was applied to prevent timing attacks, but analysis shows this may not have been fully effective. In particular it appears as if the removal of PKCS#1 padding may leak timing information, which in turn could be used to recover session key bits. In Go 1.20, the crypto/tls library switched to a fully constant time RSA implementation, which we do not believe exhibits any timing side channels.

Side Channel Attack

MS Windows IsLocal Function Fails to Detect Reserved Device Names (CVE-2023-45284)
CVE-2023-45284 5.3 - Medium - November 09, 2023

On Windows, The IsLocal function does not correctly detect reserved device names in some cases. Reserved names followed by spaces, such as "COM1 ", and reserved names "COM" and "LPT" followed by superscript 1, 2, or 3, are incorrectly reported as local. With fix, IsLocal now correctly reports these names as non-local.

Go filepath RLD path issue (1.20.11/1.21.4)
CVE-2023-45283 7.5 - High - November 09, 2023

The filepath package does not recognize paths with a \??\ prefix as special. On Windows, a path beginning with \??\ is a Root Local Device path equivalent to a path beginning with \\?\. Paths with a \??\ prefix may be used to access arbitrary locations on the system. For example, the path \??\c:\x is equivalent to the more common path c:\x. Before fix, Clean could convert a rooted path such as \a\..\??\b into the root local device path \??\b. Clean will now convert this to .\??\b. Similarly, Join(\, ??, b) could convert a seemingly innocent sequence of path elements into the root local device path \??\b. Join will now convert this to \.\??\b. In addition, with fix, IsAbs now correctly reports paths beginning with \??\ as absolute, and VolumeName correctly reports the \??\ prefix as a volume name. UPDATE: Go 1.20.11 and Go 1.21.4 inadvertently changed the definition of the volume name in Windows paths starting with \?, resulting in filepath.Clean(\?\c:) returning \?\c: rather than \?\c:\ (among other effects). The previous behavior has been restored.

Directory traversal

Go Templates unescaped backticks pre-1.21JS injection
CVE-2023-29453 9.8 - Critical - October 12, 2023

Templates do not properly consider backticks (`) as Javascript string delimiters, and do not escape them as expected. Backticks are used, since ES6, for JS template literals. If a template contains a Go template action within a Javascript template literal, the contents of the action can be used to terminate the literal, injecting arbitrary Javascript code into the Go template. As ES6 template literals are rather complex, and themselves can do string interpolation, the decision was made to simply disallow Go template actions from being used inside of them (e.g., "var a = {{.}}"), since there is no obviously safe way to allow this behavior. This takes the same approach as github.com/google/safehtml. With fix, Template. Parse returns an Error when it encounters templates like this, with an ErrorCode of value 12. This ErrorCode is currently unexported but will be exported in the release of Go 1.21. Users who rely on the previous behavior can re-enable it using the GODEBUG flag jstmpllitinterp=1, with the caveat that backticks will now be escaped. This should be used with caution.

Code Injection

Go HTTP/2 Server Resource Exhaustion via Rapid Reset Races
CVE-2023-39325 7.5 - High - October 11, 2023

A malicious HTTP/2 client which rapidly creates requests and immediately resets them can cause excessive server resource consumption. While the total number of requests is bounded by the http2.Server.MaxConcurrentStreams setting, resetting an in-progress request allows the attacker to create a new request while the existing one is still executing. With the fix applied, HTTP/2 servers now bound the number of simultaneously executing handler goroutines to the stream concurrency limit (MaxConcurrentStreams). New requests arriving when at the limit (which can only happen after the client has reset an existing, in-flight request) will be queued until a handler exits. If the request queue grows too large, the server will terminate the connection. This issue is also fixed in golang.org/x/net/http2 for users manually configuring HTTP/2. The default stream concurrency limit is 250 streams (requests) per HTTP/2 connection. This value may be adjusted using the golang.org/x/net/http2 package; see the Server.MaxConcurrentStreams setting and the ConfigureServer function.

Allocation of Resources Without Limits or Throttling

HTTP/2 DoS via Stream Reset in nginx
CVE-2023-44487 7.5 - High - October 10, 2023

The HTTP/2 protocol allows a denial of service (server resource consumption) because request cancellation can reset many streams quickly, as exploited in the wild in August through October 2023.

Resource Exhaustion

Go Compiler Line Directive Exploit Bypasses cgo Restrictions
CVE-2023-39323 8.1 - High - October 05, 2023

Line directives ("//line") can be used to bypass the restrictions on "//go:cgo_" directives, allowing blocked linker and compiler flags to be passed during compilation. This can result in unexpected execution of arbitrary code when running "go build". The line directive requires the absolute path of the file in which the directive lives, which makes exploiting this issue significantly more complex.

Go html/template XSS from mishandled comment tokens in <script> tags
CVE-2023-39318 6.1 - Medium - September 08, 2023

The html/template package does not properly handle HTML-like "" comment tokens, nor hashbang "#!" comment tokens, in <script> contexts. This may cause the template parser to improperly interpret the contents of <script> contexts, causing actions to be improperly escaped. This may be leveraged to perform an XSS attack.

XSS

Go html/template XSS via improper script handling
CVE-2023-39319 6.1 - Medium - September 08, 2023

The html/template package does not apply the proper rules for handling occurrences of "<script", "<!--", and "</script" within JS literals in <script> contexts. This may cause the template parser to improperly consider script contexts to be terminated early, causing actions to be improperly escaped. This could be leveraged to perform an XSS attack.

XSS

Go 1.21 Toolchain RCE via go.mod
CVE-2023-39320 9.8 - Critical - September 08, 2023

The go.mod toolchain directive, introduced in Go 1.21, can be leveraged to execute scripts and binaries relative to the root of the module when the "go" command was executed within the module. This applies to modules downloaded using the "go" command from the module proxy, as well as modules downloaded directly using VCS software.

Code Injection

quic-go Incomplete Post-Handshake Message Panic (CVE-2023-39321)
CVE-2023-39321 7.5 - High - September 08, 2023

Processing an incomplete post-handshake message for a QUIC connection can cause a panic.

Unbounded memory growth via oversized QUIC posthandshake messages
CVE-2023-39322 7.5 - High - September 08, 2023

QUIC connections do not set an upper bound on the amount of data buffered when reading post-handshake messages, allowing a malicious QUIC connection to cause unbounded memory growth. With fix, connections now consistently reject messages larger than 65KiB in size.

Allocation of Resources Without Limits or Throttling

Resource Exhaustion via Large RSA Keys in go-libp2p <0.27.8 <0.28.2 <0.29.1
CVE-2023-39533 7.5 - High - August 08, 2023

go-libp2p is the Go implementation of the libp2p Networking Stack. Prior to versions 0.27.8, 0.28.2, and 0.29.1 malicious peer can use large RSA keys to run a resource exhaustion attack & force a node to spend time doing signature verification of the large key. This vulnerability is present in the core/crypto module of go-libp2p and can occur during the Noise handshake and the libp2p x509 extension verification step. To prevent this attack, go-libp2p versions 0.27.8, 0.28.2, and 0.29.1 restrict RSA keys to <= 8192 bits. To protect one's application, it is necessary to update to these patch releases and to use the updated Go compiler in 1.20.7 or 1.19.12. There are no known workarounds for this issue.

Allocation of Resources Without Limits or Throttling

Large RSA Keys in Go crypto/tls Causing CPU Exhaustion
CVE-2023-29409 5.3 - Medium - August 02, 2023

Extremely large RSA keys in certificate chains can cause a client/server to expend significant CPU time verifying signatures. With fix, the size of RSA keys transmitted during handshakes is restricted to <= 8192 bits. Based on a survey of publicly trusted RSA keys, there are currently only three certificates in circulation with keys larger than this, and all three appear to be test certificates that are not actively deployed. It is possible there are larger keys in use in private PKIs, but we target the web PKI, so causing breakage here in the interests of increasing the default safety of users of crypto/tls seems reasonable.

Resource Exhaustion

Go HTTP Client Host Header Injection Vulnerability
CVE-2023-29406 6.5 - Medium - July 11, 2023

The HTTP/1 client does not fully validate the contents of the Host header. A maliciously crafted Host header can inject additional headers or entire requests. With fix, the HTTP/1 client now refuses to send requests containing an invalid Request.Host or Request.URL.Host value.

Interpretation Conflict

Go CLI cgo newline bug generates unexpected code
CVE-2023-29402 9.8 - Critical - June 08, 2023

The go command may generate unexpected code at build time when using cgo. This may result in unexpected behavior when running a go program which uses cgo. This may occur when running an untrusted module which contains directories with newline characters in their names. Modules which are retrieved using the go command, i.e. via "go get", are not affected (modules retrieved using GOPATH-mode, i.e. GO111MODULE=off, may be affected).

Code Injection

Go Runtime Setuid/setgid PrivEsc via I/O Descriptors
CVE-2023-29403 7.8 - High - June 08, 2023

On Unix platforms, the Go runtime does not behave differently when a binary is run with the setuid/setgid bits. This can be dangerous in certain cases, such as when dumping memory state, or assuming the status of standard i/o file descriptors. If a setuid/setgid binary is executed with standard I/O file descriptors closed, opening any files can result in unexpected content being read or written with elevated privileges. Similarly, if a setuid/setgid program is terminated, either via panic or signal, it may leak the contents of its registers.

Exposure of Resource to Wrong Sphere

Go gccgo LDFLAGS Smuggling Cmd Exec in Build Time
CVE-2023-29405 9.8 - Critical - June 08, 2023

The go command may execute arbitrary code at build time when using cgo. This may occur when running "go get" on a malicious module, or when running any other command which builds untrusted code. This is can by triggered by linker flags, specified via a "#cgo LDFLAGS" directive. Flags containing embedded spaces are mishandled, allowing disallowed flags to be smuggled through the LDFLAGS sanitization by including them in the argument of another flag. This only affects usage of the gccgo compiler.

Injection

Go cgo Exec Arbitrary Code via LDFLAGS Sanitization
CVE-2023-29404 9.8 - Critical - June 08, 2023

The go command may execute arbitrary code at build time when using cgo. This may occur when running "go get" on a malicious module, or when running any other command which builds untrusted code. This is can by triggered by linker flags, specified via a "#cgo LDFLAGS" directive. The arguments for a number of flags which are non-optional are incorrectly considered optional, allowing disallowed flags to be smuggled through the LDFLAGS sanitization. This affects usage of both the gc and gccgo compilers.

Code Injection

Go html/template Unquoted Attribute Injection via Empty Input
CVE-2023-29400 7.3 - High - May 11, 2023

Templates containing actions in unquoted HTML attributes (e.g. "attr={{.}}") executed with empty input can result in output with unexpected results when parsed due to HTML normalization rules. This may allow injection of arbitrary attributes into tags.

Injection

JS whitespace sanitization flaw in template engine
CVE-2023-24540 9.8 - Critical - May 11, 2023

Not all valid JavaScript whitespace characters are considered to be whitespace. Templates containing whitespace characters outside of the character set "\t\n\f\r\u0020\u2028\u2029" in JavaScript contexts that also contain actions may not be properly sanitized during execution.

Handlebars.js CSS Injection via Unescaped Action Delimiters
CVE-2023-24539 7.3 - High - May 11, 2023

Angle brackets (<>) are not considered dangerous characters when inserted into CSS contexts. Templates containing multiple actions separated by a '/' character can result in unexpectedly closing the CSS context and allowing for injection of unexpected HTML, if executed with untrusted input.

Injection

Traefik 2.x Header Parsing DoS via Excessive Memory Allocation
CVE-2023-29013 7.5 - High - April 14, 2023

Traefik (pronounced traffic) is a modern HTTP reverse proxy and load balancer for deploying microservices. There is a vulnerability in Go when parsing the HTTP headers, which impacts Traefik. HTTP header parsing could allocate substantially more memory than required to hold the parsed headers. This behavior could be exploited to cause a denial of service. This issue has been patched in versions 2.9.10 and 2.10.0-rc2.

Resource Exhaustion

DoS via Header Parsing Over-Allocation in HTTP/MIME Processing
CVE-2023-24534 7.5 - High - April 06, 2023

HTTP and MIME header parsing can allocate large amounts of memory, even when parsing small inputs, potentially leading to a denial of service. Certain unusual patterns of input data can cause the common function used to parse HTTP and MIME headers to allocate substantially more memory than required to hold the parsed headers. An attacker can exploit this behavior to cause an HTTP server to allocate large amounts of memory from a small request, potentially leading to memory exhaustion and a denial of service. With fix, header parsing now correctly allocates only the memory required to hold parsed headers.

Resource Exhaustion

Go Template package JS injection via backticks (before Go 1.21)
CVE-2023-24538 9.8 - Critical - April 06, 2023

Templates do not properly consider backticks (`) as Javascript string delimiters, and do not escape them as expected. Backticks are used, since ES6, for JS template literals. If a template contains a Go template action within a Javascript template literal, the contents of the action can be used to terminate the literal, injecting arbitrary Javascript code into the Go template. As ES6 template literals are rather complex, and themselves can do string interpolation, the decision was made to simply disallow Go template actions from being used inside of them (e.g. "var a = {{.}}"), since there is no obviously safe way to allow this behavior. This takes the same approach as github.com/google/safehtml. With fix, Template.Parse returns an Error when it encounters templates like this, with an ErrorCode of value 12. This ErrorCode is currently unexported, but will be exported in the release of Go 1.21. Users who rely on the previous behavior can re-enable it using the GODEBUG flag jstmpllitinterp=1, with the caveat that backticks will now be escaped. This should be used with caution.

Code Injection

Go Parse Overlarge //line Directives Causing Infinite Loop
CVE-2023-24537 7.5 - High - April 06, 2023

Calling any of the Parse functions on Go source code which contains //line directives with very large line numbers can cause an infinite loop due to integer overflow.

Integer Overflow or Wraparound