{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-65625", "assignerOrgId": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "state": "PUBLISHED", "assignerShortName": "EEF", "dateReserved": "2026-07-22T13:55:59.401Z", "datePublished": "2026-10-26T19:52:54.987Z", "dateUpdated": "2026-10-26T19:52:54.987Z"}, "containers": {"cna": {"affected": [{"collectionURL": "https://repo.hex.pm", "cpes": ["cpe:2.3:a:potatosalad:jose:*:*:*:*:*:*:*:*"], "defaultStatus": "unaffected", "modules": ["jose_jwa_aes"], "packageName": "jose", "packageURL": "pkg:hex/jose", "product": "jose", "programFiles": ["src/jwa/jose_jwa_aes.erl"], "programRoutines": [{"name": "jose_jwa_aes:block_decrypt/4"}, {"name": "jose_jwa_aes:gcm_block_decrypt/6"}], "repo": "https://github.com/potatosalad/erlang-jose", "vendor": "potatosalad", "versions": [{"lessThan": "1.11.13", "status": "affected", "version": "1.2.0", "versionType": "semver"}]}, {"collectionURL": "https://github.com", "cpes": ["cpe:2.3:a:potatosalad:jose:*:*:*:*:*:*:*:*"], "defaultStatus": "unaffected", "modules": ["jose_jwa_aes"], "packageName": "potatosalad/erlang-jose", "packageURL": "pkg:github/potatosalad/erlang-jose", "product": "jose", "programFiles": ["src/jwa/jose_jwa_aes.erl"], "programRoutines": [{"name": "jose_jwa_aes:block_decrypt/4"}, {"name": "jose_jwa_aes:gcm_block_decrypt/6"}], "repo": "https://github.com/potatosalad/erlang-jose", "vendor": "potatosalad", "versions": [{"lessThan": "3fa1f8e3efda0da5ce6f4c9984789f979dc02740", "status": "affected", "version": "8848b172575fb7d7e1e2977e8ae0a21678d2157a", "versionType": "git"}]}], "configurations": [{"lang": "en", "supportingMedia": [{"base64": false, "type": "text/html", "value": "<p>This vulnerability is only exploitable when AES-GCM is handled by the pure-Erlang <code>jose_jwa_aes</code> fallback. That fallback is used on deployments where the Erlang/OTP <code>crypto</code> 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 <code>crypto</code> and are not affected.</p>"}, {"base64": false, "type": "text/markdown", "value": "This 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."}], "value": "This 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."}], "cpeApplicability": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:potatosalad:jose:*:*:*:*:*:*:*:*", "versionEndExcluding": "1.11.13", "versionStartIncluding": "1.2.0", "vulnerable": true}], "negate": false, "operator": "OR"}], "operator": "AND"}], "credits": [{"lang": "en", "type": "reporter", "value": "Peter Ullrich"}, {"lang": "en", "type": "remediation developer", "value": "Andrew Bennett"}, {"lang": "en", "type": "analyst", "value": "Jonatan M\u00e4nnchen / EEF"}], "descriptions": [{"lang": "en", "supportingMedia": [{"base64": false, "type": "text/html", "value": "<p>The pure-Erlang AES-GCM fallback in <code>jose_jwa_aes</code> derives the number of verified authentication tag bits from the attacker-supplied tag itself. In the <code>{aes_gcm, Bits}</code> clause of <code>block_decrypt/4</code>, the incoming tag is guarded only by <code>is_binary/1</code>, with no check on its length. Verification in <code>gcm_block_decrypt/6</code> then computes <code>TBits = bit_size(T)</code> 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.</p>\n<p>This issue affects jose: from 1.2.0 before 1.11.13.</p>"}, {"base64": false, "type": "text/markdown", "value": "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."}], "value": "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."}], "impacts": [{"capecId": "CAPEC-475", "descriptions": [{"lang": "en", "value": "CAPEC-475 Signature Spoofing by Improper Validation"}]}], "metrics": [{"cvssV4_0": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "attackVector": "LOCAL", "baseScore": 5.9, "baseSeverity": "MEDIUM", "privilegesRequired": "NONE", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "userInteraction": "NONE", "valueDensity": "NOT_DEFINED", "vectorString": "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", "version": "4.0", "vulnAvailabilityImpact": "LOW", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "HIGH", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}]}], "problemTypes": [{"descriptions": [{"cweId": "CWE-354", "description": "CWE-354 Improper Validation of Integrity Check Value", "lang": "en", "type": "CWE"}]}], "providerMetadata": {"orgId": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "shortName": "EEF", "dateUpdated": "2026-10-26T19:52:54.987Z"}, "references": [{"tags": ["vendor-advisory", "related"], "url": "https://github.com/potatosalad/erlang-jose/security/advisories/GHSA-6gxw-6f7r-cjr6"}, {"name": "EEF CNA record for CVE-2026-65625", "tags": ["related"], "url": "https://cna.erlef.org/cves/CVE-2026-65625.html"}, {"name": "OSV record EEF-CVE-2026-65625", "tags": ["related"], "url": "https://osv.dev/vulnerability/EEF-CVE-2026-65625"}, {"name": "Introducing commit 8848b17 in potatosalad/erlang-jose", "tags": ["related"], "url": "https://github.com/potatosalad/erlang-jose/commit/8848b172575fb7d7e1e2977e8ae0a21678d2157a"}, {"name": "Fix commit 3fa1f8e in potatosalad/erlang-jose", "tags": ["patch"], "url": "https://github.com/potatosalad/erlang-jose/commit/3fa1f8e3efda0da5ce6f4c9984789f979dc02740"}], "source": {"discovery": "EXTERNAL"}, "title": "Attacker-controlled AES-GCM authentication tag length allows tag forgery in jose", "workarounds": [{"lang": "en", "supportingMedia": [{"base64": false, "type": "text/html", "value": "<p>Ensure 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 <code>crypto</code> NIF instead of the <code>jose_jwa_aes</code> fallback.</p>"}, {"base64": false, "type": "text/markdown", "value": "Ensure 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."}], "value": "Ensure 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."}]}}}

{}

{"affected": [{"affectedData": [{"collectionURL": "https://repo.hex.pm", "cpes": ["cpe:2.3:a:potatosalad:jose:*:*:*:*:*:*:*:*"], "defaultStatus": "unaffected", "modules": ["jose_jwa_aes"], "packageName": "jose", "packageURL": "pkg:hex/jose", "product": "jose", "programFiles": ["src/jwa/jose_jwa_aes.erl"], "programRoutines": [{"name": "jose_jwa_aes:block_decrypt/4"}, {"name": "jose_jwa_aes:gcm_block_decrypt/6"}], "repo": "https://github.com/potatosalad/erlang-jose", "vendor": "potatosalad", "versions": [{"lessThan": "1.11.13", "status": "affected", "version": "1.2.0", "versionType": "semver"}]}, {"collectionURL": "https://github.com", "cpes": ["cpe:2.3:a:potatosalad:jose:*:*:*:*:*:*:*:*"], "defaultStatus": "unaffected", "modules": ["jose_jwa_aes"], "packageName": "potatosalad/erlang-jose", "packageURL": "pkg:github/potatosalad/erlang-jose", "product": "jose", "programFiles": ["src/jwa/jose_jwa_aes.erl"], "programRoutines": [{"name": "jose_jwa_aes:block_decrypt/4"}, {"name": "jose_jwa_aes:gcm_block_decrypt/6"}], "repo": "https://github.com/potatosalad/erlang-jose", "vendor": "potatosalad", "versions": [{"lessThan": "3fa1f8e3efda0da5ce6f4c9984789f979dc02740", "status": "affected", "version": "8848b172575fb7d7e1e2977e8ae0a21678d2157a", "versionType": "git"}]}], "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "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."}], "id": "CVE-2026-65625", "lastModified": "2026-10-26T20:17:57.910", "metrics": {"cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "attackVector": "LOCAL", "availabilityRequirement": "NOT_DEFINED", "baseScore": 5.9, "baseSeverity": "MEDIUM", "confidentialityRequirement": "NOT_DEFINED", "exploitMaturity": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "privilegesRequired": "NONE", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "userInteraction": "NONE", "valueDensity": "NOT_DEFINED", "vectorString": "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", "version": "4.0", "vulnAvailabilityImpact": "LOW", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "HIGH", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "type": "Secondary"}]}, "published": "2026-10-26T20:17:57.910", "references": [{"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "url": "https://cna.erlef.org/cves/CVE-2026-65625.html"}, {"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "url": "https://github.com/potatosalad/erlang-jose/commit/3fa1f8e3efda0da5ce6f4c9984789f979dc02740"}, {"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "url": "https://github.com/potatosalad/erlang-jose/commit/8848b172575fb7d7e1e2977e8ae0a21678d2157a"}, {"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "url": "https://github.com/potatosalad/erlang-jose/security/advisories/GHSA-6gxw-6f7r-cjr6"}, {"source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "url": "https://osv.dev/vulnerability/EEF-CVE-2026-65625"}], "sourceIdentifier": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-354"}], "source": "6b3ad84c-e1a6-4bf7-a703-f496b71e49db", "type": "Secondary"}]}

{}

{}