{"items":[{"id":"NVI-00009008","kind":"vulnerability","title":"Authlib JWS JWK Header Injection: Signature Verification Bypass","revision":4,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-wvwj-cvrp-7pv5","CVE-2026-27962"],"plain_summary":"GitHub lists this reviewed advisory for authlib. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.","review_status":"source_listed","control_topics":[],"public_actions":[{"summary":"Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.","source_ids":["sr-047d82365318eb288998b965ccba0c81"],"action_type":"investigate","limitations":"Confirm current vendor support, compatibility and deployment evidence. 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Null normalizes fields.","title":"GHSA-wvwj-cvrp-7pv5","publisher":"GitHub Advisory Database","observed_at":"2026-10-31T21:56:51.534Z"},{"id":"sr-047d82365318eb288998b965ccba0c81","url":"https://www.first.org/epss/data.html","basis":"official_catalog","notes":"FIRST EPSS; probability of exploitation in the next 30 days, not local compromise. Dataset date/model retained; FIRST services terms apply.","title":"CVE-2026-27962","publisher":"FIRST EPSS","observed_at":"2026-11-06T00:24:57.650Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-71206e102bf5ad83a7f2658c4bee4cdf"],"technology":"authlib","known_exclusions":[],"conditions_summary":"## Description\n\n### Summary\n\nA JWK Header Injection vulnerability in `authlib`'s JWS implementation allows an unauthenticated\nattacker to forge arbitrary JWT tokens that pass signature verification. When `key=None` is passed\nto any JWS deserialization function, the library extracts and uses the cryptographic key embedded\nin the attacker-controlled JWT `jwk` header field. An attacker can sign a token with their own\nprivate key, embed the matching public key in the header, and have the server accept the forged\ntoken as cryptographically valid — bypassing authentication and authorization entirely.\n\nThis behavior violates **RFC 7515 §4.1.3** and the validation algorithm defined in **RFC 7515 §5.2**.\n\n### Details\n\n**Vulnerable file:** `authlib/jose/rfc7515/jws.py`  \n**Vulnerable method:** `JsonWebSignature._prepare_algorithm_key()`  \n**Lines:** 272–273\n\n```python\nelif key is None and \"jwk\" in header:\n    key = header[\"jwk\"]   # ← attacker-controlled key used for verification\n```\n\nWhen `key=None` is passed to `jws.deserialize_compact()`, `jws.deserialize_json()`, or\n`jws.deserialize()`, the library checks the JWT header for a `jwk` field. If present, it extracts\nthat value — which is ful","public_affected_ranges":["<= 1.6.8"]}],"null_published_at":"2026-11-07T07:07:46.827Z","source_updated_at":"2026-10-27T15:22:32.000Z","source_disclosed_at":"2026-03-16T15:17:15.000Z","is_synthetic_fixture":false,"null_last_reviewed_at":null,"public_change_summary":"Dated EPSS estimate updated; this is not a new disclosure or proof of exploitation.","null_first_observed_at":"2026-10-31T21:56:51.534Z"},{"id":"NVI-00009008","kind":"vulnerability","title":"Authlib JWS JWK Header Injection: Signature Verification Bypass","revision":3,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-wvwj-cvrp-7pv5","CVE-2026-27962"],"plain_summary":"GitHub lists this reviewed advisory for authlib. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.","review_status":"source_listed","control_topics":[],"public_actions":[{"summary":"Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.","source_ids":["sr-14a5dd21f5fa48ec90da88d5795c4293"],"action_type":"investigate","limitations":"Confirm current vendor support, compatibility and deployment evidence. 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Null normalizes fields.","title":"GHSA-wvwj-cvrp-7pv5","publisher":"GitHub Advisory Database","observed_at":"2026-10-31T21:56:51.534Z"},{"id":"sr-14a5dd21f5fa48ec90da88d5795c4293","url":"https://www.first.org/epss/data.html","basis":"official_catalog","notes":"FIRST EPSS; probability of exploitation in the next 30 days, not local compromise. Dataset date/model retained; FIRST services terms apply.","title":"CVE-2026-27962","publisher":"FIRST EPSS","observed_at":"2026-11-03T17:44:07.781Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-71206e102bf5ad83a7f2658c4bee4cdf"],"technology":"authlib","known_exclusions":[],"conditions_summary":"## Description\n\n### Summary\n\nA JWK Header Injection vulnerability in `authlib`'s JWS implementation allows an unauthenticated\nattacker to forge arbitrary JWT tokens that pass signature verification. When `key=None` is passed\nto any JWS deserialization function, the library extracts and uses the cryptographic key embedded\nin the attacker-controlled JWT `jwk` header field. An attacker can sign a token with their own\nprivate key, embed the matching public key in the header, and have the server accept the forged\ntoken as cryptographically valid — bypassing authentication and authorization entirely.\n\nThis behavior violates **RFC 7515 §4.1.3** and the validation algorithm defined in **RFC 7515 §5.2**.\n\n### Details\n\n**Vulnerable file:** `authlib/jose/rfc7515/jws.py`  \n**Vulnerable method:** `JsonWebSignature._prepare_algorithm_key()`  \n**Lines:** 272–273\n\n```python\nelif key is None and \"jwk\" in header:\n    key = header[\"jwk\"]   # ← attacker-controlled key used for verification\n```\n\nWhen `key=None` is passed to `jws.deserialize_compact()`, `jws.deserialize_json()`, or\n`jws.deserialize()`, the library checks the JWT header for a `jwk` field. If present, it extracts\nthat value — which is ful","public_affected_ranges":["<= 1.6.8"]}],"null_published_at":"2026-11-06T00:29:57.321Z","source_updated_at":"2026-10-27T15:22:32.000Z","source_disclosed_at":"2026-03-16T15:17:15.000Z","is_synthetic_fixture":false,"null_last_reviewed_at":null,"public_change_summary":"Dated EPSS estimate updated; this is not a new disclosure or proof of exploitation.","null_first_observed_at":"2026-10-31T21:56:51.534Z"},{"id":"NVI-00009008","kind":"vulnerability","title":"Authlib JWS JWK Header Injection: Signature Verification Bypass","revision":2,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-wvwj-cvrp-7pv5","CVE-2026-27962"],"plain_summary":"GitHub lists this reviewed advisory for authlib. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.","review_status":"source_listed","control_topics":[],"public_actions":[{"summary":"Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.","source_ids":["sr-311827aa27d96396fe9108a3359d6ace"],"action_type":"investigate","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null}],"schema_version":"1.1.0","source_metrics":[{"kind":"CVSS","as_of":"2026-10-27T15:22:32.000Z","value":"9.1 critical","meaning":"GitHub source severity; exploitability and local consequence require separate evidence.","source_id":"sr-71206e102bf5ad83a7f2658c4bee4cdf"},{"kind":"EPSS","as_of":"2026-10-31T12:00:27.000Z","value":"0.558%","meaning":"FIRST EPSS model v2026.06.15; exploitation probability over 30 days, percentile 0.46497. Missing scores are unknown.","source_id":"sr-311827aa27d96396fe9108a3359d6ace"}],"why_it_matters":"Published affected context helps an owner decide what evidence to gather. This report has not examined your application.","related_sources":[{"id":"sr-71206e102bf5ad83a7f2658c4bee4cdf","url":"https://github.com/advisories/GHSA-wvwj-cvrp-7pv5","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-wvwj-cvrp-7pv5","publisher":"GitHub Advisory Database","observed_at":"2026-10-31T21:56:51.534Z"},{"id":"sr-311827aa27d96396fe9108a3359d6ace","url":"https://www.first.org/epss/data.html","basis":"official_catalog","notes":"FIRST EPSS; probability of exploitation in the next 30 days, not local compromise. Dataset date/model retained; FIRST services terms apply.","title":"CVE-2026-27962","publisher":"FIRST EPSS","observed_at":"2026-10-31T22:06:15.376Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-71206e102bf5ad83a7f2658c4bee4cdf"],"technology":"authlib","known_exclusions":[],"conditions_summary":"## Description\n\n### Summary\n\nA JWK Header Injection vulnerability in `authlib`'s JWS implementation allows an unauthenticated\nattacker to forge arbitrary JWT tokens that pass signature verification. When `key=None` is passed\nto any JWS deserialization function, the library extracts and uses the cryptographic key embedded\nin the attacker-controlled JWT `jwk` header field. An attacker can sign a token with their own\nprivate key, embed the matching public key in the header, and have the server accept the forged\ntoken as cryptographically valid — bypassing authentication and authorization entirely.\n\nThis behavior violates **RFC 7515 §4.1.3** and the validation algorithm defined in **RFC 7515 §5.2**.\n\n### Details\n\n**Vulnerable file:** `authlib/jose/rfc7515/jws.py`  \n**Vulnerable method:** `JsonWebSignature._prepare_algorithm_key()`  \n**Lines:** 272–273\n\n```python\nelif key is None and \"jwk\" in header:\n    key = header[\"jwk\"]   # ← attacker-controlled key used for verification\n```\n\nWhen `key=None` is passed to `jws.deserialize_compact()`, `jws.deserialize_json()`, or\n`jws.deserialize()`, the library checks the JWT header for a `jwk` field. If present, it extracts\nthat value — which is ful","public_affected_ranges":["<= 1.6.8"]}],"null_published_at":"2026-10-31T22:27:15.283Z","source_updated_at":"2026-10-27T15:22:32.000Z","source_disclosed_at":"2026-03-16T15:17:15.000Z","is_synthetic_fixture":false,"null_last_reviewed_at":null,"public_change_summary":"Dated EPSS estimate updated; this is not a new disclosure or proof of exploitation.","null_first_observed_at":"2026-10-31T21:56:51.534Z"},{"id":"NVI-00009008","kind":"vulnerability","title":"Authlib JWS JWK Header Injection: Signature Verification Bypass","revision":1,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-wvwj-cvrp-7pv5","CVE-2026-27962"],"plain_summary":"GitHub lists this reviewed advisory for authlib. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.","review_status":"source_listed","control_topics":[],"public_actions":[{"summary":"Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.","source_ids":["sr-71206e102bf5ad83a7f2658c4bee4cdf"],"action_type":"investigate","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null}],"schema_version":"1.1.0","source_metrics":[{"kind":"CVSS","as_of":"2026-10-27T15:22:32.000Z","value":"9.1 critical","meaning":"GitHub source severity; exploitability and local consequence require separate evidence.","source_id":"sr-71206e102bf5ad83a7f2658c4bee4cdf"}],"why_it_matters":"Published affected context helps an owner decide what evidence to gather. This report has not examined your application.","related_sources":[{"id":"sr-71206e102bf5ad83a7f2658c4bee4cdf","url":"https://github.com/advisories/GHSA-wvwj-cvrp-7pv5","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-wvwj-cvrp-7pv5","publisher":"GitHub Advisory Database","observed_at":"2026-10-31T21:56:51.534Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-71206e102bf5ad83a7f2658c4bee4cdf"],"technology":"authlib","known_exclusions":[],"conditions_summary":"## Description\n\n### Summary\n\nA JWK Header Injection vulnerability in `authlib`'s JWS implementation allows an unauthenticated\nattacker to forge arbitrary JWT tokens that pass signature verification. When `key=None` is passed\nto any JWS deserialization function, the library extracts and uses the cryptographic key embedded\nin the attacker-controlled JWT `jwk` header field. An attacker can sign a token with their own\nprivate key, embed the matching public key in the header, and have the server accept the forged\ntoken as cryptographically valid — bypassing authentication and authorization entirely.\n\nThis behavior violates **RFC 7515 §4.1.3** and the validation algorithm defined in **RFC 7515 §5.2**.\n\n### Details\n\n**Vulnerable file:** `authlib/jose/rfc7515/jws.py`  \n**Vulnerable method:** `JsonWebSignature._prepare_algorithm_key()`  \n**Lines:** 272–273\n\n```python\nelif key is None and \"jwk\" in header:\n    key = header[\"jwk\"]   # ← attacker-controlled key used for verification\n```\n\nWhen `key=None` is passed to `jws.deserialize_compact()`, `jws.deserialize_json()`, or\n`jws.deserialize()`, the library checks the JWT header for a `jwk` field. If present, it extracts\nthat value — which is ful","public_affected_ranges":["<= 1.6.8"]}],"null_published_at":"2026-10-31T22:13:27.127Z","source_updated_at":"2026-10-27T15:22:32.000Z","source_disclosed_at":"2026-03-16T15:17:15.000Z","is_synthetic_fixture":false,"null_last_reviewed_at":null,"public_change_summary":"First indexed by Null; source disclosure date is shown separately.","null_first_observed_at":"2026-10-31T21:56:51.534Z"}],"next_cursor":null,"snapshot_revision":"42594"}