{"affected":[{"ranges":[{"events":[{"introduced":"84adefa331c4159d432d22840663c38f155cd4c1"},{"fixed":"07d2d0e93f6aaf7652a81e8df075fc1728da5e96"}],"repo":"https://github.com/erlang/otp","type":"GIT"}]}],"aliases":["GHSA-gf6r-99xw-6qg6","CVE-2026-54891"],"credits":[{"name":"Lukas Backström","type":"FINDER"},{"name":"Ingela Anderton Andin","type":"REMEDIATION_DEVELOPER"},{"name":"Dan Gudmundsson","type":"REMEDIATION_REVIEWER"},{"name":"Jakub Witczak","type":"REMEDIATION_REVIEWER"}],"database_specific":{"capec_ids":["CAPEC-94"],"cpe_ids":["cpe:2.3:a:erlang:erlang\\/otp:*:*:*:*:*:*:*:*"],"cwe_ids":["CWE-924"]},"details":"## Summary\n\nImproper Enforcement of Message Integrity During Transmission in a Communication Channel vulnerability in Erlang/OTP ssl (tls\\_gen\\_connection module) allows a network-positioned attacker to inject unauthenticated plaintext that the TLS client application later treats as authenticated server data.\n\nThe function tls\\_gen\\_connection:handle\\_protocol\\_record/3 rejects APPLICATION\\_DATA records that arrive in pre-handshake states when the TLS endpoint acts as a server, but does not apply the same check when the endpoint acts as a client. A network-positioned attacker can send plaintext APPLICATION\\_DATA records to the client during the handshake. The records are buffered and, once the handshake completes successfully, delivered to the application as if they were authenticated post-handshake data. The attacker cannot observe the client's response or steer the connection, so the impact is limited to blind injection of unauthenticated bytes. The injection window is wider for TLS versions prior to TLS 1.3 than for TLS 1.3.\n\nThis vulnerability is associated with program file lib/ssl/src/tls\\_gen\\_connection.erl.\n\nThis issue affects OTP from OTP 17.0 before 29.0.3, 28.5.0.3 and 27.3.4.14 corresponding to ssl from 5.3.4 before 11.7.3, 11.6.0.3 and 11.2.12.10. TLS 1.3 is affected starting with OTP 22.0, when TLS 1.3 support was added.","id":"EEF-CVE-2026-54891","modified":"2026-07-02T16:06:30.982Z","published":"2026-07-02T16:06:30.982Z","references":[{"type":"ADVISORY","url":"https://github.com/erlang/otp/security/advisories/GHSA-gf6r-99xw-6qg6"},{"type":"WEB","url":"https://cna.erlef.org/cves/CVE-2026-54891.html"},{"type":"WEB","url":"https://www.erlang.org/doc/system/versions.html#order-of-versions"},{"type":"FIX","url":"https://github.com/erlang/otp/commit/07d2d0e93f6aaf7652a81e8df075fc1728da5e96"}],"related":[],"schema_version":"1.7.3","severity":[{"score":"CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N","type":"CVSS_V4"}],"summary":"Plaintext APPLICATION_DATA injected during TLS handshake delivered to client application post-handshake in ssl","upstream":[]}