{"id":"CVE-2026-65625","aliases":["AZL-112187","DEBIAN-CVE-2026-65625","EEF-CVE-2026-65625","EUVD-2026-110303","GHSA-6gxw-6f7r-cjr6","UBUNTU-CVE-2026-65625"],"status":"published","title":"Attacker-controlled AES-GCM authentication tag length allows tag forgery in jose","description":"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.","severity":{"version":"4.0","score":5.9,"vector":"CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.00115,"percentile":0.01566,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-354"],"published":"2026-10-26T19:52:54Z","modified":"2026-11-10T04:00:09Z","fixes":[{"ecosystem":"Debian:14","package":"erlang-jose","fixed_in":["1.11.13-1"],"sources":["osv"]},{"ecosystem":"Hex","package":"jose","fixed_in":["1.11.13"],"sources":["osv"]}],"affected":[{"source":"osv","ecosystem":"Azure Linux:3","package":"rabbitmq-server","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"3.13.7-10"}]}]},{"source":"osv","ecosystem":"Debian:12","package":"erlang-jose","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.11.10-1","1.11.10-1~bpo12+1","1.11.12-1","1.11.12-1.1","1.11.12-2","1.11.12-2~bpo13+1","1.11.12-3","1.11.12-3~bpo13+1","1.11.13-1","1.11.5-1","1.11.6-1","1.11.6-1~bpo12+1"]},{"source":"osv","ecosystem":"Debian:13","package":"erlang-jose","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.11.10-1","1.11.12-1","1.11.12-1.1","1.11.12-2","1.11.12-2~bpo13+1","1.11.12-3","1.11.12-3~bpo13+1","1.11.13-1"]},{"source":"osv","ecosystem":"Debian:14","package":"erlang-jose","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.11.13-1"}]}],"versions":["1.11.10-1","1.11.12-1","1.11.12-1.1","1.11.12-2","1.11.12-2~bpo13+1","1.11.12-3","1.11.12-3~bpo13+1"]},{"source":"osv","ecosystem":"Hex","package":"jose","ranges":[{"type":"SEMVER","events":[{"introduced":"1.2.0"},{"fixed":"1.11.13"}]}],"versions":["1.10.0","1.10.1","1.11.0","1.11.1","1.11.10","1.11.11","1.11.12","1.11.2","1.11.4","1.11.5","1.11.6","1.11.7","1.11.8","1.11.9","1.2.0","1.3.0","1.4.0","1.4.1","1.4.2","1.5.0","1.5.1","1.5.2","1.6.0","1.6.1","1.7.0","1.7.1","1.7.2","1.7.3","1.7.4","1.7.5","1.7.6","1.7.7","1.7.8","1.7.9","1.8.0","1.8.1","1.8.2","1.8.3","1.8.4","1.9.0"]},{"source":"osv","ecosystem":"Ubuntu:18.04:LTS","package":"jose","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["10-2","10-2build1"]},{"source":"osv","ecosystem":"Ubuntu:20.04:LTS","package":"jose","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["10-2build2"]},{"source":"osv","ecosystem":"Ubuntu:22.04:LTS","package":"jose","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["10-3","11-2"]},{"source":"osv","ecosystem":"Ubuntu:24.04:LTS","package":"jose","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["11-2","11-3","11-3build1","11-3build2","13-1"]},{"source":"osv","ecosystem":"Ubuntu:26.10","package":"jose","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["14-2build1","14-2build2"]},{"source":"osv","ecosystem":"Ubuntu:26.04:LTS","package":"jose","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["14-2build1"]}],"products":[{"vendor":"appsup-dart","product":"jose"},{"vendor":"potatosalad","product":"jose"}],"references":[{"url":"https://github.com/potatosalad/erlang-jose/security/advisories/GHSA-6gxw-6f7r-cjr6","tags":["vendor-advisory","related","advisory"]},{"url":"https://cna.erlef.org/cves/CVE-2026-65625.html","tags":["related","web"]},{"url":"https://osv.dev/vulnerability/EEF-CVE-2026-65625","tags":["related","web"]},{"url":"https://github.com/potatosalad/erlang-jose/commit/8848b172575fb7d7e1e2977e8ae0a21678d2157a","tags":["related","fix","web","report"]},{"url":"https://github.com/potatosalad/erlang-jose/commit/3fa1f8e3efda0da5ce6f4c9984789f979dc02740","tags":["patch","fix","report"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-65625","tags":["web","advisory"]},{"url":"https://github.com","tags":["web","report"]},{"url":"https://repo.hex.pm","tags":["web","report"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/65xxx/CVE-2026-65625.json","tags":["advisory"]},{"url":"https://github.com/potatosalad/erlang-jose","tags":["package","report"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2026-65625","tags":["advisory"]},{"url":"https://hex.pm/packages/jose","tags":["package","report"]},{"url":"https://ubuntu.com/security/CVE-2026-65625","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-65625","tags":["report"]},{"url":"https://cna.erlef.org/cves/cve-2026-65625.html","tags":["report"]},{"url":"https://github.com/potatosalad/erlang-jose/security/advisories/ghsa-6gxw-6f7r-cjr6","tags":["report"]},{"url":"https://github.com/cveproject/cvelistv5/tree/main/cves/2026/65xxx/cve-2026-65625.json","tags":["report"]},{"url":"https://nvd.nist.gov/vuln/detail/cve-2026-65625","tags":["report"]},{"url":"https://osv.dev/vulnerability/eef-cve-2026-65625","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2026-65625","title":"Attacker-controlled AES-GCM authentication tag length allows tag forgery in jose","description":"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.","status":"published","published":"2026-10-26T19:52:54.987Z","modified":"2026-11-02T19:43:05.255Z","cvss":[{"version":"4.0","score":5.9,"vector":"CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N","level":"medium","assessor":"cna"}],"cwes":["CWE-354"],"updated_at":"2026-11-02T20:51:25.833244Z"}],"euvd":[{"id":"EUVD-2026-110303","description":"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.","status":"published","published":"2026-10-26T19:52:54Z","modified":"2026-11-02T19:43:05Z","cvss":[{"version":"4.0","score":5.9,"vector":"CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N","level":"medium"}],"updated_at":"2026-11-03T05:08:38.228652Z"}],"nvd":[{"id":"CVE-2026-65625","description":"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.","status":"published","published":"2026-10-26T20:17:57.91Z","modified":"2026-11-02T20:17:58.62Z","cvss":[{"version":"4.0","score":5.9,"vector":"CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:L/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","level":"medium","assessor":"secondary"}],"cwes":["CWE-354"],"updated_at":"2026-11-03T00:02:36.126212Z"}],"osv":[{"id":"CVE-2026-65625","title":"Attacker-controlled AES-GCM authentication tag length allows tag forgery in jose","description":"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.","status":"published","published":"2026-10-26T19:52:54.987Z","modified":"2026-11-11T10:47:33.341160048Z","cvss":[{"version":"4.0","score":5.9,"vector":"CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N","level":"medium"}],"cwes":["CWE-354"],"updated_at":"2026-11-11T03:22:28.447808Z"},{"id":"DEBIAN-CVE-2026-65625","description":"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.  This issue affects jose: from 1.2.0 before 1.11.13.","status":"published","published":"2026-10-26T20:17:57.91Z","modified":"2026-11-10T04:00:09.824487599Z","cvss":[{"version":"4.0","score":5.9,"vector":"CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:L/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","level":"medium"}],"updated_at":"2026-11-10T04:22:10.004764Z"},{"id":"EEF-CVE-2026-65625","title":"Attacker-controlled AES-GCM authentication tag length allows tag forgery in jose","description":"## Summary\n\nThe 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.\n\n## Workarounds\n\nEnsure the runtime provides a crypto provider with native AES-GCM support (a standard Erlang/OTP build linked against OpenSSL) so that JOSE dispatches AES-GCM to the native `crypto` NIF instead of the `jose_jwa_aes` fallback.\n\n## Configurations\n\nThis vulnerability is only exploitable when AES-GCM is handled by the pure-Erlang `jose_jwa_aes` fallback. That fallback is used on deployments where the Erlang/OTP `crypto` NIF does not expose native AES-GCM (for example FIPS builds, or stripped or older OTP releases). Deployments with a native AES-GCM crypto provider dispatch GCM through `crypto` and are not affected.","status":"published","published":"2026-10-26T19:52:54.987Z","modified":"2026-10-26T20:11:07.497402732Z","cvss":[{"version":"4.0","score":5.9,"vector":"CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N","level":"medium"}],"cwes":["CWE-354"],"updated_at":"2026-11-02T15:46:33.520522Z"},{"id":"UBUNTU-CVE-2026-65625","description":"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. This issue affects jose: from 1.2.0 before 1.11.13.","status":"published","published":"2026-10-26T20:17:00Z","modified":"2026-10-28T20:17:34.857348214Z","cvss":[{"version":"4.0","score":5.9,"vector":"CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N","level":"medium"},{"version":"4.0","score":5.9,"vector":"CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N","level":"medium"}],"updated_at":"2026-11-02T16:56:53.710209Z"},{"id":"AZL-112187","title":"CVE-2026-65625 affecting package rabbitmq-server 3.13.7-10","description":"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.","status":"published","published":"2026-10-26T20:17:57Z","modified":"2026-11-03T05:33:06Z","updated_at":"2026-11-05T16:41:19.001909Z"}]}}