Live › vulnerability › CVE-2026-117666
ssl_verify_fun is an Erlang library that checks TLS certificate hostnames. A partial-label wildcard such as f*.example.net wrongly matches names like f.evil.example.net, so an attacker in the middle can impersonate a TLS peer.
Summary written from the sources below. Check the originals before acting.
First seen by InfraStack 2026-10-30 21:25 UTC. All times on this page are UTC.
Exposed are Erlang clients that disable SNI, servers that verify client certificate hostnames with this library, and code that calls verify_cert_hostname/2 directly. Erlang/OTP 20.0 and later check the hostname in ssl before the user verify_fun runs, so clients that keep server_name_indication set are protected regardless.
No product ranges from the sources yet.
ssl_verify_fun dependency in your Erlang project's lock file or rebar.lock, and note its version.verify_cert_hostname/2 directly.ssl_verify_fun 1.1.8 or later (fixed in versions from before )1.0.11.1.8Each row is the first time that source carried this signal. The analyst’s rows are its own findings.
Improper Validation of Certificate with Host Mismatch vulnerability in deadtrickster ssl_verify_fun allows an adversary in the middle to impersonate a TLS peer via a certificate that carries a partial-label wildcard. try_match_wildcard/4 in src/ssl_verify_hostname.erl anchors only the text before and after the * of an identifier such as f*.example.net, so the wildcard also consumes dots and the certificate is accepted for f.evil.example.net. RFC 6125 confines a wildcard to the left-most label. The same matcher lets *.168.1.1 match the IP literal 192.168.1.1. Whole-label wildcards are matched correctly.
Erlang/OTP 20.0 and later check the hostname in ssl before a user verify_fun sees valid_peer, so a client that keeps server_name_indication set rejects the mismatch regardless. Exposed are clients that disable SNI, servers that verify client certificate hostnames with this library, and direct callers of verify_cert_hostname/2.
This issue affects ssl_verify_fun: from 1.0.1 before 1.1.8.
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