{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-102271", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-09-28T20:11:16.658Z", "datePublished": "2026-09-28T20:31:53.066Z", "dateUpdated": "2026-09-28T20:31:53.066Z"}, "containers": {"cna": {"title": "PyJWT: Public keys in DER form are accepted as HMAC secrets, bypassing the CVE-2022-29217 guard", "problemTypes": [{"descriptions": [{"cweId": "CWE-347", "lang": "en", "description": "CWE-347: Improper Verification of Cryptographic Signature", "type": "CWE"}]}], "metrics": [{"cvssV3_1": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 7.4, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N", "version": "3.1"}}], "references": [{"name": "https://github.com/jpadilla/pyjwt/security/advisories/GHSA-p4g4-x82p-q773", "tags": ["x_refsource_CONFIRM"], "url": "https://github.com/jpadilla/pyjwt/security/advisories/GHSA-p4g4-x82p-q773"}, {"name": "https://github.com/jpadilla/pyjwt/commit/2798504fa2663364573cf2d1043d8d7fef389499", "tags": ["x_refsource_MISC"], "url": "https://github.com/jpadilla/pyjwt/commit/2798504fa2663364573cf2d1043d8d7fef389499"}, {"name": "https://github.com/jpadilla/pyjwt/releases/tag/2.14.0", "tags": ["x_refsource_MISC"], "url": "https://github.com/jpadilla/pyjwt/releases/tag/2.14.0"}], "affected": [{"vendor": "jpadilla", "product": "pyjwt", "versions": [{"version": ">= 2.4.0, < 2.14.0", "status": "affected"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-09-28T20:31:53.066Z"}, "descriptions": [{"lang": "en", "value": "PyJWT is a Python implementation of JSON Web Token standards. From 2.4.0 until 2.14.0, PyJWT HMACAlgorithm.prepare_key is affected because asymmetric-key guard relies on textual markers that are absent from DER encoding. This occurs when an application mixes HMAC and asymmetric algorithms and supplies a DER public key as the shared verification key. As a result, PyJWT uses public DER bytes as an HMAC secret. Consequently, an attacker who knows the public key can forge authenticated HMAC tokens. This issue is fixed in version 2.14.0."}], "source": {"advisory": "GHSA-p4g4-x82p-q773", "discovery": "UNKNOWN"}}}}

{}

{"affected": [{"affectedData": [{"product": "pyjwt", "vendor": "jpadilla", "versions": [{"status": "affected", "version": ">= 2.4.0, < 2.14.0"}]}], "source": "security-advisories@github.com"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "PyJWT is a Python implementation of JSON Web Token standards. From 2.4.0 until 2.14.0, PyJWT HMACAlgorithm.prepare_key is affected because asymmetric-key guard relies on textual markers that are absent from DER encoding. This occurs when an application mixes HMAC and asymmetric algorithms and supplies a DER public key as the shared verification key. As a result, PyJWT uses public DER bytes as an HMAC secret. Consequently, an attacker who knows the public key can forge authenticated HMAC tokens. This issue is fixed in version 2.14.0."}], "id": "CVE-2026-102271", "lastModified": "2026-09-28T21:17:15.110", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 7.4, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N", "version": "3.1"}, "exploitabilityScore": 2.2, "impactScore": 5.2, "source": "security-advisories@github.com", "type": "Secondary"}]}, "published": "2026-09-28T21:17:15.110", "references": [{"source": "security-advisories@github.com", "url": "https://github.com/jpadilla/pyjwt/commit/2798504fa2663364573cf2d1043d8d7fef389499"}, {"source": "security-advisories@github.com", "url": "https://github.com/jpadilla/pyjwt/releases/tag/2.14.0"}, {"source": "security-advisories@github.com", "url": "https://github.com/jpadilla/pyjwt/security/advisories/GHSA-p4g4-x82p-q773"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-347"}], "source": "security-advisories@github.com", "type": "Primary"}]}

{"bugzilla": {"description": "pyjwt: PyJWT: Authentication bypass via acceptance of DER public keys as HMAC secrets", "id": "2542687", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2542687"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.4", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N", "status": "draft"}, "cwe": "CWE-347", "details": ["A flaw was found in PyJWT. The library fails to identify asymmetric public keys supplied in Distinguished Encoding Rules (DER) format, inadvertently treating the public data as a shared secret in Hash-based Message Authentication Code (HMAC) operations. If an application supports both asymmetric and symmetric signing algorithms, a remote attacker knowing the public key can exploit this flaw to forge valid authentication tokens and bypass access controls."], "name": "CVE-2026-102271", "package_state": [{"cpe": "cpe:/a:redhat:hummingbird:1", "fix_state": "Not affected", "package_name": "jaeger", "product_name": "Red Hat Hardened Images"}, {"cpe": "cpe:/a:redhat:hummingbird:1", "fix_state": "Not affected", "package_name": "llvm21", "product_name": "Red Hat Hardened Images"}, {"cpe": "cpe:/a:redhat:hummingbird:1", "fix_state": "Not affected", "package_name": "rust", "product_name": "Red Hat Hardened Images"}, {"cpe": "cpe:/a:redhat:hummingbird:1", "fix_state": "Not affected", "package_name": "swift-lang", "product_name": "Red Hat Hardened Images"}], "public_date": "2026-09-28T20:31:53Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-102271\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-102271\nhttps://github.com/jpadilla/pyjwt/commit/2798504fa2663364573cf2d1043d8d7fef389499\nhttps://github.com/jpadilla/pyjwt/releases/tag/2.14.0\nhttps://github.com/jpadilla/pyjwt/security/advisories/GHSA-p4g4-x82p-q773"], "threat_severity": "Important"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[2.4.0,2.14.0)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "pyjwt", "source": "cna", "vendor": "jpadilla"}, "product": "pyjwt", "vendor": "jpadilla"}], "created": "2026-09-28T22:00:09.947441+00:00", "updated": "2026-09-28T22:15:08.591409+00:00", "vendors": ["jpadilla", "jpadilla$PRODUCT$pyjwt"]}