CVE-2026-89422: Erlang OTP · Key Exchange Without Entity Authentication
Affects Erlang OTPSource CVE Database V5
Not known to be exploited · CVSS 9.3 Critical : upgrade to 11.2.12.13 as a priority.
Data as of 5 Nov 2026, 23:24 UTC
- EPSS
- 0.4% chance of exploitation in 30 days – higher than 39% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 11.2.12.13
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 22 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 6 Nov 2026.
What to do
Upgrade ssl to 11.2.12.13.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| ErlangOTP | Affected
| Fixed in– |
| ErlangOTP | Affected
| Fixed in– |
| ErlangOTP | Affected
| Fixed in– |
GitHubsslpkg:github/sslOther threats | Affected
| Fixed in
|
CPE configurations (1)
cpe:2.3:a:erlang:erlang\/otp:*:*:*:*:*:*:*:*
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A fix is available in Erlang/OTP versions 27.3.4.18, 28.5.0.7, and 29.1.1, and corresponding ssl versions 11.2.12.13, 11.6.0.6, and 11.7.7. Users should upgrade to these or later versions to remediate the vulnerability. There is no indication that the vulnerability is mitigated by configuration changes alone. Patch status is confirmed by the vendor advisory information.
Description
Key Exchange without Entity Authentication vulnerability in Erlang/OTP ssl allows a peer that answers a TLS 1.3 client connection to impersonate the intended server. A pre_shared_key extension in the ServerHello that the client never offered causes the client to complete the handshake without validating the server's certificate, so ssl:connect returns {ok, Socket} against a peer holding no certificate, no private key and no prior session. tls_client_connection_1_3:handle_server_hello/2 passes the received extension to tls_gen_connection_1_3:handle_resumption/2, which sets resumption = true on its mere presence without checking that the client offered a PSK. tls_handshake_1_3:get_pre_shared_key/4 meanwhile falls back to the all-zero "no PSK" value and keys the handshake with the ordinary non-PSK schedule, so the attacker's own ephemeral key suffices. The resumption flag then routes maybe_resumption/1 straight to wait_finished, skipping the certificate-handling states, so certificate path validation, verify_fun, hostname verification, partial_chain, CRL checking and OCSP stapling are all bypassed. The default client configuration is affected; clients restricted to TLS 1.2 are not. This issue affects OTP from OTP 22.2 before OTP 27.3.4.18, OTP 28.5.0.7, and OTP 29.1.1, corresponding to ssl from 9.5 before 11.2.12.13, 11.6.0.6, and 11.7.7.
References
- github.com/erlang/otp/security/advisories/GHSA-rgxr-4g4w-j875 (opens in a new tab)
- cna.erlef.org/cves/CVE-2026-89422.html (opens in a new tab)
- osv.dev/vulnerability/EEF-CVE-2026-89422 (opens in a new tab)
- erlang.org/doc/system/versions.html (opens in a new tab)
- github.com/erlang/otp/commit/21b8a1b0ad0adf200682b3854bc50114ab2b8c62 (opens in a new tab)
- github.com/erlang/otp/commit/afec5156361bb50d3607c7c1a453c19b9149b324 (opens in a new tab)
- github.com/erlang/otp/commit/98c66c858113949c4262d26cd7d426c4b09d2b35 (opens in a new tab)
- github.com/erlang/otp/commit/fd1d9d07fc92ec0d59f96dfb66182195882bb7dd (opens in a new tab)