CVE-2026-54887
MediumCVSS 4.8Exploitation Probability (EPSS)
Low risk16th percentile - higher than 16% of all known CVEs
Summary
Use of Default Cryptographic Key vulnerability in Erlang/OTP ssl (DTLS server) allows predictable DTLS cookie computation during the startup window, enabling source address verification bypass. On DTLS server startup, dtls_server_connection:initial_hello/3 initializes previous_cookie_secret to the empty binary instead of a random value. Because HMAC with an empty key is deterministic, anyone who observes the plaintext ClientHello can compute a valid DTLS cookie before the first rotation of the cookie secret.
Risk Assessment
The risk is that an attacker can bypass source address verification, enabling DTLS handshake amplification with spoofed source addresses, potentially leading to DoS attacks.
Recommendation
It is recommended to upgrade Erlang/OTP to version 29.0.3, 28.5.0.3, or 27.3.4.14, depending on the version in use.
Other vulnerabilities in Erlang/OTP
See all- CVE-2026-28808Critical
In Erlang OTP (inets module), an incorrect authorization vulnerability exists. When script_alias maps a URL prefix to a directory outside DocumentRoot, mod_auth evaluates directory access controls against the DocumentRoot path while mod_cgi executes the script at the ScriptAlias path. This mismatch allows unauthenticated access to CGI scripts protected by directory rules.
- 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-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-2026-58227High
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.
- CVE-2026-55953High
The TLS 1.2 (and earlier) and DTLS client in Erlang/OTP does not verify that the cipher suite selected by the server in ServerHello was among the suites offered by the client. An on-path attacker can select an anonymous cipher suite, bypassing certificate and hostname verification, allowing interception and modification of traffic.
- CVE-2026-55737High
In Erlang OTP, a signed to unsigned conversion error and out-of-bounds heap write vulnerability exists when decoding a crafted ETF binary via binary_to_term/1. This can corrupt the BEAM heap pointer and crash the virtual machine.
- CVE-2026-54890High
A vulnerability in the External Term Format (ETF) decoder in ERTS causes an integer underflow when processing crafted binary data. This leads to allocating huge memory and crashing the entire Erlang/VM node.
- CVE-2026-47078Medium
In the zip module of Erlang OTP stdlib, a relative path traversal vulnerability allows writing files outside the intended extraction directory via a crafted zip archive. The zip:check_dir_level/2 function improperly validates paths containing ../ sequences.
- CVE-2026-42792High
In Erlang OTP (epmd), a connection slot exhaustion vulnerability allows an unauthenticated remote attacker to permanently terminate the epmd daemon. The do_accept function incorrectly treats EMFILE/ENFILE errors as fatal instead of recoverable.
- CVE-2026-55952High
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.
Original NVD description (English source)
Use of Default Cryptographic Key vulnerability in Erlang/OTP ssl (DTLS server) allows predictable DTLS cookie computation during the startup window, enabling source address verification bypass. On DTLS server startup, dtls_server_connection:initial_hello/3 initializes previous_cookie_secret to the empty binary (<<>>) instead of a random value. Because HMAC with an empty key is deterministic, anyone who observes the plaintext ClientHello can compute dtls_handshake:cookie(<<>>, IP, Port, Hello) and forge a valid DTLS cookie before the first rotation of the cookie secret. The DTLS cookie (RFC 6347 §4.2.1) is a denial-of-service mitigation that prevents spoofed source IPs from forcing the server to allocate state and perform expensive cryptographic operations; it is not an authentication mechanism. During the window from server startup until the first secret rotation (0 to 15 seconds), an attacker who can observe the plaintext ClientHello can bypass the source address verification, enabling DTLS handshake amplification with spoofed source addresses. This vulnerability is associated with program file lib/ssl/src/dtls_server_connection.erl and program routine dtls_server_connection:initial_hello/3. This issue affects OTP from OTP 20.0 before OTP 29.0.3, OTP 28.5.0.3 and OTP 27.3.4.14, corresponding to ssl from 8.2 before 11.7.3, 11.6.0.3 and 11.2.12.10.