{"timestamp":"2026-07-02T17:28:09.569991Z","id":"CVE-2026-55952","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}

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 22.2 before 29.0.3, 28.5.0.3 and 27.3.4.14 corresponding to ssl from 9.5 before 11.7.3, 11.6.0.3 and 11.2.12.10.

AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

CWE-1284

https://cna.erlef.org/cves/CVE-2026-55952.html

https://github.com/erlang/otp/commit/2c3e599797644310e5d4aa39c7193420e59dadff

https://github.com/erlang/otp/commit/9b5437c72fa3403a75c1aba28e5c532bc191c662

https://github.com/erlang/otp/commit/e77823e6d980b2ec0b4fe4ea3f2d098ca239e3ce

https://github.com/erlang/otp/security/advisories/GHSA-8c57-44c9-pc59

https://osv.dev/vulnerability/EEF-CVE-2026-55952

https://www.erlang.org/doc/system/versions.html#order-of-versions

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