Erlang/OTP -- (D)TLS-1.2 server certificate verification bypass

2026-07-27 · CVE-2026-55953 · VuXML entry

https://github.com/erlang/otp/security/advisories/GHSA-c6cw-pr89-w882 reports: The OTP TLS/DTLS client (pre TLS-1.3) does not verify that the cipher suite selected by the server in ServerHello is one of those offered in ClientHello. A man-in-the-middle attacker can select an anonymous cipher suite such as ECDH_anon that was never offered by the client. Since anonymous suites do not require a server certificate, this …

Affected versions

• erlang < 28.5.0.4,4
• erlang-runtime27 < 27.3.4.15
• erlang-runtime28 < 28.5.0.4
• erlang-runtime29 < 29.0.4

By system

3 still vulnerable, 4 fixed. Where VuXML applies (FreeBSD, DragonFly, FreeBSD's derivatives) a port is vulnerable while its version is in a range; pkgsrc says itself whether it lists a CVE of this advisory; OpenBSD and MidnightBSD keep no list this site reads, so their row is only an estimate: FreeBSD's ranges applied to upstream's version.