CVE-2026-105236
MediumCVSS 6.3Summary
Improper certificate validation in the ssl application in Erlang/OTP allows a client holding a certificate trusted by one SNI virtual host to authenticate to a second SNI virtual host on the same listener by resuming its TLS 1.2 session there. A server serving multiple SNI names from one listen socket keeps one shared session cache and does not bind a cached session to the SNI name or client trust policy that established it. This affects OTP from 18.0 before 27.3.4.19, 28.5.0.8, and 29.1.2.
Risk Assessment
A client with a certificate trusted by one SNI host can access a second SNI host, bypassing client authentication policy. This may lead to unauthorized access to protected resources.
Recommendation
Upgrade Erlang/OTP to version 27.3.4.19, 28.5.0.8, or 29.1.2. If possible, disable TLS 1.2 session resumption for servers requiring client authentication.
Other vulnerabilities in Erlang/OTP
See all- CVE-2026-94200High
Erlang OTP ssl (tls_handshake_1_3, ssl_handshake and tls_client_ticket_store modules) has an improper validation of consistency within input. A malicious TLS 1.3 server can cause a denial of service of the ssl application on the client node by sending a NewSessionTicket message with invalid extensions.
- CVE-2026-28808Critical
An incorrect authorization vulnerability in Erlang OTP (inets modules) allows unauthenticated access to CGI scripts protected by directory rules when served via script_alias. The path mismatch between access control evaluation and script execution allows bypassing protections.
- CVE-2026-23941Critical
In Erlang OTP (inets httpd module), an HTTP Request Smuggling vulnerability exists. The server does not reject or normalize duplicate Content-Length headers. The first value is used, while common proxies use the last, enabling front-end/back-end desynchronization and injection of attacker-controlled bytes as the start of the next request.
- CVE-2025-32433CriticalActively exploited
Erlang/OTP prior to versions OTP-27.3.3, OTP-26.2.5.11, and OTP-25.3.2.20 contains a vulnerability in the SSH server that 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 and execute arbitrary commands without valid credentials.
- CVE-2016-10253Critical
An issue was discovered in Erlang/OTP 18.x related to the generation of compiled regular expressions, which is vulnerable to a heap overflow. Regular expressions using a malformed extpattern can indirectly specify an offset used as an array index.
- CVE-2026-75538High
In Erlang/OTP, when using the inet driver with {packet,4} mode, an attacker connecting to an open TCP port can exploit a signed overflow in packet length calculation, potentially overflowing the receive buffer and crashing the BEAM VM.
- CVE-2026-74835High
The httpd HTTP server in the inets application fails to enforce a configured body-size limit on chunked requests. This may allow sending very large requests, potentially leading to server overload.
- CVE-2026-73812High
The check_header/3 function in httpd rejects duplicate Content-Length but does not check for the co-presence of Transfer-Encoding and Content-Length, which can lead to request smuggling desynchronization between front-end and back-end.
- CVE-2026-73276High
Gracefulness code ignored cases that should be rejected, resulting in possible HTTP Request Smuggling opportunities.
- CVE-2026-58227High
A vulnerability in the Erlang/OTP SSL application allows memory exhaustion by sending a crafted certificate chain during TLS/DTLS handshake. Lack of cycle detection in the certificate chain building function causes unbounded recursion, leading to BEAM node crash.
Original NVD description (English source)
Improper Certificate Validation vulnerability in the ssl application in Erlang/OTP allows a client that holds a certificate trusted by one SNI virtual host to authenticate to a second SNI virtual host on the same listener by resuming its TLS 1.2 session there. A server that serves several SNI names from one listen socket through sni_fun or sni_hosts keeps one pre-TLS 1.3 session cache per listener and does not bind a cached session to the SNI name or client trust policy that established it. When an SNI option set switches to verify_peer without naming reuse_sessions, ssl_config:update_options/3 inherits the base listener's reuse_sessions value of true, so the default that disables reuse for client-authenticating servers does not apply. On an abbreviated handshake ssl_session:is_resumable/4 checks only that the cached session uses one of the current server certificates and carries some peer certificate, and never revalidates that certificate against the CA selected for the requested name. The names must share a server certificate, which is common with wildcard or multi-SAN certificates. TLS 1.3 does not use this cache and is not affected. This issue affects OTP from OTP 18.0 before OTP 27.3.4.19, OTP 28.5.0.8, and OTP 29.1.2, corresponding to ssl from 7.0 before 11.2.12.14, 11.6.0.7, and 11.7.8.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS