Erlangotp

HTTP Request Smuggling in Erlang OTP (inets) before v28.4.1
CVE-2026-23941 - March 13, 2026

Inconsistent Interpretation of HTTP Requests ('HTTP Request Smuggling') vulnerability in Erlang OTP (inets httpd module) allows HTTP Request Smuggling. This vulnerability is associated with program files lib/inets/src/http_server/httpd_request.erl and program routines httpd_request:parse_headers/7. The server does not reject or normalize duplicate Content-Length headers. The earliest Content-Length in the request is used for body parsing while common reverse proxies (nginx, Apache httpd, Envoy) honor the last Content-Length value. This violates RFC 9112 Section 6.3 and allows front-end/back-end desynchronization, leaving attacker-controlled bytes queued as the start of the next request. This issue affects OTP from OTP 17.0 until OTP 28.4.1, OTP 27.3.4.9 and OTP 26.2.5.18, corresponding to inets from 5.10 until 9.6.1, 9.3.2.3 and 9.1.0.5.

HTTP Request Smuggling

Erlang OTP SSH Transport Compression Bomb OOM (OTP 17.028.4.1)
CVE-2026-23943 - March 13, 2026

Improper Handling of Highly Compressed Data (Compression Bomb) vulnerability in Erlang OTP ssh (ssh_transport modules) allows Denial of Service via Resource Depletion. The SSH transport layer advertises legacy zlib compression by default and inflates attacker-controlled payloads pre-authentication without any size limit, enabling reliable memory exhaustion DoS. Two compression algorithms are affected: * zlib: Activates immediately after key exchange, enabling unauthenticated attacks * zlib@openssh.com: Activates post-authentication, enabling authenticated attacks Each SSH packet can decompress ~255 MB from 256 KB of wire data (1029:1 amplification ratio). Multiple packets can rapidly exhaust available memory, causing OOM kills in memory-constrained environments. This vulnerability is associated with program files lib/ssh/src/ssh_transport.erl and program routines ssh_transport:decompress/2, ssh_transport:handle_packet_part/4. This issue affects OTP from OTP 17.0 until OTP 28.4.1, 27.3.4.9 and 26.2.5.18 corresponding to ssh from 3.0.1 until 5.5.1, 5.2.11.6 and 5.1.4.14.

Data Amplification

Erlang OTP ssh_sftpd Path Traversal (prefix) before 28.4.2
CVE-2026-23942 - March 13, 2026

Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') vulnerability in Erlang OTP (ssh_sftpd module) allows Path Traversal. This vulnerability is associated with program files lib/ssh/src/ssh_sftpd.erl and program routines ssh_sftpd:is_within_root/2. The SFTP server uses string prefix matching via lists:prefix/2 rather than proper path component validation when checking if a path is within the configured root directory. This allows authenticated users to access sibling directories that share a common name prefix with the configured root directory. For example, if root is set to /home/user1, paths like /home/user10 or /home/user1_backup would incorrectly be considered within the root. This issue affects OTP from OTP 17.0 until OTP 28.4.1, OTP 27.3.4.9 and OTP 26.2.5.18, corresponding to ssh from 3.0.1 until 5.5.1, 5.2.11.6 and 5.1.4.14.

Directory traversal

Relative Path Traversal in Erlang OTP tftp_file (before 7.0)
CVE-2026-21620 - February 20, 2026

Relative Path Traversal, Improper Isolation or Compartmentalization vulnerability in erlang otp erlang/otp (tftp_file modules), erlang otp inets (tftp_file modules), erlang otp tftp (tftp_file modules) allows Relative Path Traversal. This vulnerability is associated with program files lib/tftp/src/tftp_file.erl, src/tftp_file.erl. This issue affects otp: from 17.0, from 07b8f441ca711f9812fad9e9115bab3c3aa92f79; otp: from 5.10 before 7.0; otp: from 1.0.

Relative Path Traversal

Erlang OTP SSH ssh_sftp Resource Exhaustion Before 5.3.3
CVE-2025-48041 - September 11, 2025

Allocation of Resources Without Limits or Throttling vulnerability in Erlang OTP ssh (ssh_sftp modules) allows Excessive Allocation, Flooding. This vulnerability is associated with program files lib/ssh/src/ssh_sftpd.erl. This issue affects OTP form OTP 17.0 until OTP 28.0.3, OTP 27.3.4.3 and 26.2.5.15 corresponding to ssh from 3.0.1 until 5.3.3, 5.2.11.3 and 5.1.4.12.

Allocation of Resources Without Limits or Throttling

Uncontrolled Resource Consumption in Erlang OTP ssh_sftp (3.0.1-5.3.3)
CVE-2025-48040 - September 11, 2025

Uncontrolled Resource Consumption vulnerability in Erlang OTP ssh (ssh_sftp modules) allows Excessive Allocation, Flooding. This vulnerability is associated with program files lib/ssh/src/ssh_sftpd.erl. This issue affects OTP form OTP 17.0 until OTP 28.0.3, OTP 27.3.4.3 and 26.2.5.15 corresponding to ssh from 3.0.1 until 5.3.3, 5.2.11.3 and 5.1.4.12.

Resource Exhaustion

Erlang OTP SSH (ssh_sftp) Excessive Resource Allocation Vulnerability pre-5.3.3
CVE-2025-48039 - September 11, 2025

Allocation of Resources Without Limits or Throttling vulnerability in Erlang OTP ssh (ssh_sftp modules) allows Excessive Allocation, Resource Leak Exposure. This vulnerability is associated with program files lib/ssh/src/ssh_sftpd.erl. This issue affects OTP form OTP 17.0 until OTP 28.0.3, OTP 27.3.4.3 and 26.2.5.15 corresponding to ssh from 3.0.1 until 5.3.3, 5.2.11.3 and 5.1.4.12.

Allocation of Resources Without Limits or Throttling

Erlang OTP SSH SFTP Leaks Resources (Excessive Allocation) before 5.3.3
CVE-2025-48038 - September 11, 2025

Allocation of Resources Without Limits or Throttling vulnerability in Erlang OTP ssh (ssh_sftp modules) allows Excessive Allocation, Resource Leak Exposure. This vulnerability is associated with program files lib/ssh/src/ssh_sftpd.erl. This issue affects OTP form OTP 17.0 until OTP 28.0.3, OTP 27.3.4.3 and 26.2.5.15 corresponding to ssh from 3.0.1 until 5.3.3, 5.2.11.3 and 5.1.4.12.

Allocation of Resources Without Limits or Throttling

CVE-2025-4748: Erlang OTP Path Traversal in stdlib:zip before 28.0.1
CVE-2025-4748 - June 16, 2025

Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') vulnerability in Erlang OTP (stdlib modules) allows Absolute Path Traversal, File Manipulation. This vulnerability is associated with program files lib/stdlib/src/zip.erl and program routines zip:unzip/1, zip:unzip/2, zip:extract/1, zip:extract/2 unless the memory option is passed. This issue affects OTP from OTP 17.0 until OTP 28.0.1, OTP 27.3.4.1 and OTP 26.2.5.13, corresponding to stdlib from 2.0 until 7.0.1, 6.2.2.1 and 5.2.3.4.

Directory traversal

Unauth RCE in Erlang/OTP SSH Server <27.3.3
CVE-2025-32433 10 - Critical - April 16, 2025

Erlang/OTP is a set of libraries for the Erlang programming language. Prior to versions OTP-27.3.3, OTP-26.2.5.11, and OTP-25.3.2.20, a SSH server may allow an attacker to perform unauthenticated remote code execution (RCE). By exploiting a flaw in SSH protocol message handling, a malicious actor could gain unauthorized access to affected systems and execute arbitrary commands without valid credentials. This issue is patched in versions OTP-27.3.3, OTP-26.2.5.11, and OTP-25.3.2.20. A temporary workaround involves disabling the SSH server or to prevent access via firewall rules.

Missing Authentication for Critical Function

OpenSSH <9.6 BPP handshake flaw allows integrity bypass (Terrapin attack)
CVE-2023-48795 5.9 - Medium - December 18, 2023

The SSH transport protocol with certain OpenSSH extensions, found in OpenSSH before 9.6 and other products, allows remote attackers to bypass integrity checks such that some packets are omitted (from the extension negotiation message), and a client and server may consequently end up with a connection for which some security features have been downgraded or disabled, aka a Terrapin attack. This occurs because the SSH Binary Packet Protocol (BPP), implemented by these extensions, mishandles the handshake phase and mishandles use of sequence numbers. For example, there is an effective attack against SSH's use of ChaCha20-Poly1305 (and CBC with Encrypt-then-MAC). The bypass occurs in chacha20-poly1305@openssh.com and (if CBC is used) the -etm@openssh.com MAC algorithms. This also affects Maverick Synergy Java SSH API before 3.1.0-SNAPSHOT, Dropbear through 2022.83, Ssh before 5.1.1 in Erlang/OTP, PuTTY before 0.80, AsyncSSH before 2.14.2, golang.org/x/crypto before 0.17.0, libssh before 0.10.6, libssh2 through 1.11.0, Thorn Tech SFTP Gateway before 3.4.6, Tera Term before 5.1, Paramiko before 3.4.0, jsch before 0.2.15, SFTPGo before 2.5.6, Netgate pfSense Plus through 23.09.1, Netgate pfSense CE through 2.7.2, HPN-SSH through 18.2.0, ProFTPD before 1.3.8b (and before 1.3.9rc2), ORYX CycloneSSH before 2.3.4, NetSarang XShell 7 before Build 0144, CrushFTP before 10.6.0, ConnectBot SSH library before 2.2.22, Apache MINA sshd through 2.11.0, sshj through 0.37.0, TinySSH through 20230101, trilead-ssh2 6401, LANCOM LCOS and LANconfig, FileZilla before 3.66.4, Nova before 11.8, PKIX-SSH before 14.4, SecureCRT before 9.4.3, Transmit5 before 5.10.4, Win32-OpenSSH before 9.5.0.0p1-Beta, WinSCP before 6.2.2, Bitvise SSH Server before 9.32, Bitvise SSH Client before 9.33, KiTTY through 0.76.1.13, the net-ssh gem 7.2.0 for Ruby, the mscdex ssh2 module before 1.15.0 for Node.js, the thrussh library before 0.35.1 for Rust, and the Russh crate before 0.40.2 for Rust.

Improper Validation of Integrity Check Value

Erlang/OTP SSL/TLS Client Auth Bypass before 25.0.2
CVE-2022-37026 9.8 - Critical - September 21, 2022

In Erlang/OTP before 23.3.4.15, 24.x before 24.3.4.2, and 25.x before 25.0.2, there is a Client Authentication Bypass in certain client-certification situations for SSL, TLS, and DTLS.

An issue was discovered in Erlang/OTP before 23.2.2
CVE-2020-35733 7.5 - High - January 15, 2021

An issue was discovered in Erlang/OTP before 23.2.2. The ssl application 10.2 accepts and trusts an invalid X.509 certificate chain to a trusted root Certification Authority.

Improper Certificate Validation

Erlang/OTP 22.3.x before 22.3.4.6 and 23.x before 23.1 allows Directory Traversal
CVE-2020-25623 7.5 - High - October 02, 2020

Erlang/OTP 22.3.x before 22.3.4.6 and 23.x before 23.1 allows Directory Traversal. An attacker can send a crafted HTTP request to read arbitrary files, if httpd in the inets application is used.

Directory traversal

Erlang/OTP before 18.0-rc1 does not properly check CBC padding bytes when terminating connections, which makes it easier for man-in-the-middle attackers to obtain cleartext data
CVE-2015-2774 5.9 - Medium - April 07, 2016

Erlang/OTP before 18.0-rc1 does not properly check CBC padding bytes when terminating connections, which makes it easier for man-in-the-middle attackers to obtain cleartext data via a padding-oracle attack, a variant of CVE-2014-3566 (aka POODLE).

Information Disclosure

The random number generator in the Crypto application before 2.0.2.2, and SSH before 2.0.5, as used in the Erlang/OTP ssh library before R14B03, uses predictable seeds based on the current time
CVE-2011-0766 - May 31, 2011

The random number generator in the Crypto application before 2.0.2.2, and SSH before 2.0.5, as used in the Erlang/OTP ssh library before R14B03, uses predictable seeds based on the current time, which makes it easier for remote attackers to guess DSA host and SSH session keys.

Cryptographic Issues