CVE-2026-55952
HighCVSS 7.5Exploitation Probability (EPSS)
Low risk39th percentile - higher than 39% of all known CVEs
Summary
Vulnerability in the Erlang/OTP ssl application. An unauthenticated attacker can send a crafted TLS 1.3 ClientHello, crashing the session ticket handler and making TLS 1.3 unusable until the ssl application is restarted.
Risk Assessment
Risk of persistent disruption of TLS 1.3 handling, potentially preventing secure TLS 1.3 connections and requiring a restart of the ssl application.
Recommendation
Upgrade Erlang/OTP to version 29.0.3, 28.5.0.3, or 27.3.4.14, depending on the branch used.
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-2026-105236Medium
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.
- 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.
Original NVD description (English source)
The Erlang/OTP ssl application does not validate that the PSK identity list and binder list carried in a TLS 1.3 ClientHello pre-shared key extension have equal length before passing them to the session ticket handler. In tls_handshake_1_3:handle_pre_shared_key/3, an OfferedPreSharedKeys record with a mismatched number of identities and binders is forwarded directly to tls_server_session_ticket:use/4, which crashes the session ticket handler process. An unauthenticated remote attacker can send a single crafted ClientHello to a TLS 1.3 server with session tickets enabled (stateful or stateless mode) and permanently disrupt session ticket handling on that listener. New TLS 1.3 handshakes complete but subsequently crash when the server attempts to issue a session ticket, effectively making TLS 1.3 unusable on the affected listener until the ssl application is restarted. TLS 1.2 connections are not affected. This issue affects OTP from OTP 22.2 before OTP 29.0.3, OTP 28.5.0.3 and OTP 27.3.4.14, corresponding to ssl from 9.5 before 11.7.3, 11.6.0.3 and 11.2.12.10.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS