{"schema":"threatline.record/2","record":{"id":"CVE-2026-65625","aliases":["GHSA-6gxw-6f7r-cjr6"],"summary":"Attacker-controlled AES-GCM authentication tag length allows tag forgery in jose","details":"The pure-Erlang AES-GCM fallback in jose_jwa_aes derives the number of verified authentication tag bits from the attacker-supplied tag itself. In the {aes_gcm, Bits} clause of block_decrypt/4, the incoming tag is guarded only by is_binary/1, with no check on its length. Verification in gcm_block_decrypt/6 then computes TBits = bit_size(T) and compares only those bits of the real 128-bit tag. An attacker who controls a JWE token can truncate the authentication tag to as little as 8 bits, so only 8 bits are ever checked. This reduces forgery resistance from 2^-128 to 2^-8, and a forged ciphertext is reliably accepted as authentic within 256 attempts without knowledge of the key (an authentication tag forgery and integrity bypass). Supplying a tag longer than 128 bits instead causes a badmatch that crashes the decrypting process. The fallback is reached through the public JWE decryption path whenever AES-GCM is not provided by a native crypto NIF, for example on FIPS or stripped or older OTP builds.\n\nThis issue affects jose: from 1.2.0 before 1.11.13.","categories":["Unclassified"],"product":"jose","vendor":"potatosalad","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-65625","source_modified_at":"2026-10-26T19:52:54.987Z","fetched_at":"2026-10-26T23:45:56.352924Z","product":"jose","vendor":"potatosalad","versions":[{"lessThan":"1.11.13","status":"affected","version":"1.2.0","versionType":"semver"}],"defaultStatus":"unaffected"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-65625","source_modified_at":"2026-10-26T19:52:54.987Z","fetched_at":"2026-10-26T23:45:56.352924Z","product":"jose","vendor":"potatosalad","versions":[{"lessThan":"3fa1f8e3efda0da5ce6f4c9984789f979dc02740","status":"affected","version":"8848b172575fb7d7e1e2977e8ae0a21678d2157a","versionType":"git"}],"defaultStatus":"unaffected"}],"fixed_versions":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-65625","source_modified_at":"2026-10-26T19:52:54.987Z","fetched_at":"2026-10-26T23:45:56.352924Z","package":{"name":"jose","ecosystem":null},"version":"1.11.13","basis":"first unaffected version stated in the CVE record"},{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-65625","source_modified_at":"2026-10-26T19:52:54.987Z","fetched_at":"2026-10-26T23:45:56.352924Z","package":{"name":"jose","ecosystem":null},"version":"3fa1f8e3efda0da5ce6f4c9984789f979dc02740","basis":"first unaffected version stated in the CVE record"}],"cvss":5.9,"severity":"Medium","kev":{"listed":false},"epss":{"probability":null,"percentile":null,"score_date":null},"published_at":"2026-10-26T19:52:54.987Z","modified_at":"2026-10-26T19:52:54.987Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-65625","fetched_at":"2026-10-26T23:45:56.352924Z","source_modified_at":"2026-10-26T19:52:54.987Z"}],"sources":["CVE List"],"references":[{"source":"CVE List","url":"https://github.com/potatosalad/erlang-jose/security/advisories/GHSA-6gxw-6f7r-cjr6","tags":["vendor-advisory","related"]},{"source":"CVE List","url":"https://cna.erlef.org/cves/CVE-2026-65625.html","tags":["related"]},{"source":"CVE List","url":"https://osv.dev/vulnerability/EEF-CVE-2026-65625","tags":["related"]},{"source":"CVE List","url":"https://github.com/potatosalad/erlang-jose/commit/8848b172575fb7d7e1e2977e8ae0a21678d2157a","tags":["related"]},{"source":"CVE List","url":"https://github.com/potatosalad/erlang-jose/commit/3fa1f8e3efda0da5ce6f4c9984789f979dc02740","tags":["patch"]}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","cvss_source":"CVE List","classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":null,"confidence":"unknown","reviewed":false},"change_timestamp":"2026-10-26T19:52:54.987Z","content_hash":"53b30354a011c08316e7b6ea459a41b73d83cc48514d3efc30406c9d6c81f729"}}