{"items":[{"id":"NVI-00013025","kind":"vulnerability","title":"PyJWT: PyJWK accepts empty HMAC keys, bypassing PyJWT's empty-key validation","revision":3,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected.","NVD lastModified does not establish freshness of every associated CPE record."],"lifecycle":"active","identifiers":["GHSA-9j54-fg26-wv3r","CVE-2026-102266"],"plain_summary":"GitHub lists this reviewed advisory for PyJWT. 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-0ebb5c35e8d046d8b4cf312df586b1d2"],"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":"2026-09-29T23:43:20.000Z","value":"7.4 high","meaning":"GitHub source severity; exploitability and local consequence require separate evidence.","source_id":"sr-3eb5a206f0add1b0e74de580ff646167"},{"kind":"CVSS","as_of":"2026-10-07T20:55:07.653Z","value":"7.4 HIGH (3.1)","meaning":"security-advisories@github.com severity; no combined Null risk score.","source_id":"sr-26dfdda1bc27d7e14273abbd00df27d4"},{"kind":"CVSS","as_of":"2026-10-07T20:55:07.653Z","value":"9.1 CRITICAL (3.1)","meaning":"nvd@nist.gov severity; no combined Null risk score.","source_id":"sr-26dfdda1bc27d7e14273abbd00df27d4"},{"kind":"EPSS","as_of":"2026-11-03T12:00:27.000Z","value":"0.225%","meaning":"FIRST EPSS model v2026.06.15; exploitation probability over 30 days, percentile 0.13209. Missing scores are unknown.","source_id":"sr-0ebb5c35e8d046d8b4cf312df586b1d2"}],"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-3eb5a206f0add1b0e74de580ff646167","url":"https://github.com/advisories/GHSA-9j54-fg26-wv3r","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-9j54-fg26-wv3r","publisher":"GitHub Advisory Database","observed_at":"2026-11-01T07:24:25.558Z"},{"id":"sr-26dfdda1bc27d7e14273abbd00df27d4","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-102266","basis":"official_catalog","notes":"This product uses data from the NVD API but is not endorsed or certified by the NVD.","title":"CVE-2026-102266","publisher":"NIST National Vulnerability Database","observed_at":"2026-11-03T09:58:04.487Z"},{"id":"sr-0ebb5c35e8d046d8b4cf312df586b1d2","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-2026-102266","publisher":"FIRST EPSS","observed_at":"2026-11-03T17:44:07.769Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-3eb5a206f0add1b0e74de580ff646167"],"technology":"PyJWT","known_exclusions":[],"conditions_summary":"### Summary\n\nA service that verifies HS256 tokens using an empty oct JWK through PyJWK, including a PyJWK obtained from PyJWKSet, can therefore accept attacker-generated tokens as authenticated.\n\nPyJWT 2.13.0 rejects an empty HMAC key when it is supplied through the raw `str`/`bytes` key path, but accepts the same zero-length key when it is supplied as a symmetric `PyJWK`.\n\nAn `oct` JWK containing an empty Base64URL key value:\n\n```json\n{\"kty\":\"oct\",\"k\":\"\"}\n```\n\nis decoded to `b\"\"`. During signature verification, the `PyJWK` path uses this decoded value directly and does not invoke the empty-key validation in `HMACAlgorithm.prepare_key`. With the default `enforce_minimum_key_length=False`, PyJWT emits a warning and proceeds with HMAC verification using the zero-length key.\n\nAn attacker can independently calculate `HMAC-SHA256(b\"\", signing_input)` and create valid HS256 JWTs with arbitrary claims. A service that verifies HS256 tokens using an empty `oct` JWK through `PyJWK` or `PyJWKSet` can therefore accept attacker-generated tokens as authenticated.\n\nThe application must already contain an empty HMAC JWK, for example because a missing Base64URL configuration or secret-manager value","public_affected_ranges":[">= 2.13.0, < 2.14.0"]}],"null_published_at":"2026-11-06T00:29:57.259Z","source_updated_at":"2026-09-29T23:43:20.000Z","source_disclosed_at":"2026-09-29T23:43:19.000Z","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":"2026-11-01T07:24:25.558Z"},{"id":"NVI-00013025","kind":"vulnerability","title":"PyJWT: PyJWK accepts empty HMAC keys, bypassing PyJWT's empty-key validation","revision":2,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected.","NVD lastModified does not establish freshness of every associated CPE record."],"lifecycle":"active","identifiers":["GHSA-9j54-fg26-wv3r","CVE-2026-102266"],"plain_summary":"GitHub lists this reviewed advisory for PyJWT. 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-26dfdda1bc27d7e14273abbd00df27d4"],"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":"2026-09-29T23:43:20.000Z","value":"7.4 high","meaning":"GitHub source severity; exploitability and local consequence require separate evidence.","source_id":"sr-3eb5a206f0add1b0e74de580ff646167"},{"kind":"CVSS","as_of":"2026-10-07T20:55:07.653Z","value":"7.4 HIGH (3.1)","meaning":"security-advisories@github.com severity; no combined Null risk score.","source_id":"sr-26dfdda1bc27d7e14273abbd00df27d4"},{"kind":"CVSS","as_of":"2026-10-07T20:55:07.653Z","value":"9.1 CRITICAL (3.1)","meaning":"nvd@nist.gov severity; no combined Null risk score.","source_id":"sr-26dfdda1bc27d7e14273abbd00df27d4"}],"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-3eb5a206f0add1b0e74de580ff646167","url":"https://github.com/advisories/GHSA-9j54-fg26-wv3r","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-9j54-fg26-wv3r","publisher":"GitHub Advisory Database","observed_at":"2026-11-01T07:24:25.558Z"},{"id":"sr-26dfdda1bc27d7e14273abbd00df27d4","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-102266","basis":"official_catalog","notes":"This product uses data from the NVD API but is not endorsed or certified by the NVD.","title":"CVE-2026-102266","publisher":"NIST National Vulnerability Database","observed_at":"2026-11-03T09:58:04.487Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-3eb5a206f0add1b0e74de580ff646167"],"technology":"PyJWT","known_exclusions":[],"conditions_summary":"### Summary\n\nA service that verifies HS256 tokens using an empty oct JWK through PyJWK, including a PyJWK obtained from PyJWKSet, can therefore accept attacker-generated tokens as authenticated.\n\nPyJWT 2.13.0 rejects an empty HMAC key when it is supplied through the raw `str`/`bytes` key path, but accepts the same zero-length key when it is supplied as a symmetric `PyJWK`.\n\nAn `oct` JWK containing an empty Base64URL key value:\n\n```json\n{\"kty\":\"oct\",\"k\":\"\"}\n```\n\nis decoded to `b\"\"`. During signature verification, the `PyJWK` path uses this decoded value directly and does not invoke the empty-key validation in `HMACAlgorithm.prepare_key`. With the default `enforce_minimum_key_length=False`, PyJWT emits a warning and proceeds with HMAC verification using the zero-length key.\n\nAn attacker can independently calculate `HMAC-SHA256(b\"\", signing_input)` and create valid HS256 JWTs with arbitrary claims. A service that verifies HS256 tokens using an empty `oct` JWK through `PyJWK` or `PyJWKSet` can therefore accept attacker-generated tokens as authenticated.\n\nThe application must already contain an empty HMAC JWK, for example because a missing Base64URL configuration or secret-manager value","public_affected_ranges":[">= 2.13.0, < 2.14.0"]}],"null_published_at":"2026-11-03T10:03:31.384Z","source_updated_at":"2026-09-29T23:43:20.000Z","source_disclosed_at":"2026-09-29T23:43:19.000Z","is_synthetic_fixture":false,"null_last_reviewed_at":null,"public_change_summary":"Source facts changed; compare the preserved prior revision.","null_first_observed_at":"2026-11-01T07:24:25.558Z"},{"id":"NVI-00013025","kind":"vulnerability","title":"PyJWT: PyJWK accepts empty HMAC keys, bypassing PyJWT's empty-key validation","revision":1,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-9j54-fg26-wv3r","CVE-2026-102266"],"plain_summary":"GitHub lists this reviewed advisory for PyJWT. 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-3eb5a206f0add1b0e74de580ff646167"],"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":"2026-09-29T23:43:20.000Z","value":"7.4 high","meaning":"GitHub source severity; exploitability and local consequence require separate evidence.","source_id":"sr-3eb5a206f0add1b0e74de580ff646167"}],"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-3eb5a206f0add1b0e74de580ff646167","url":"https://github.com/advisories/GHSA-9j54-fg26-wv3r","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-9j54-fg26-wv3r","publisher":"GitHub Advisory Database","observed_at":"2026-11-01T07:24:25.558Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-3eb5a206f0add1b0e74de580ff646167"],"technology":"PyJWT","known_exclusions":[],"conditions_summary":"### Summary\n\nA service that verifies HS256 tokens using an empty oct JWK through PyJWK, including a PyJWK obtained from PyJWKSet, can therefore accept attacker-generated tokens as authenticated.\n\nPyJWT 2.13.0 rejects an empty HMAC key when it is supplied through the raw `str`/`bytes` key path, but accepts the same zero-length key when it is supplied as a symmetric `PyJWK`.\n\nAn `oct` JWK containing an empty Base64URL key value:\n\n```json\n{\"kty\":\"oct\",\"k\":\"\"}\n```\n\nis decoded to `b\"\"`. During signature verification, the `PyJWK` path uses this decoded value directly and does not invoke the empty-key validation in `HMACAlgorithm.prepare_key`. With the default `enforce_minimum_key_length=False`, PyJWT emits a warning and proceeds with HMAC verification using the zero-length key.\n\nAn attacker can independently calculate `HMAC-SHA256(b\"\", signing_input)` and create valid HS256 JWTs with arbitrary claims. A service that verifies HS256 tokens using an empty `oct` JWK through `PyJWK` or `PyJWKSet` can therefore accept attacker-generated tokens as authenticated.\n\nThe application must already contain an empty HMAC JWK, for example because a missing Base64URL configuration or secret-manager value","public_affected_ranges":[">= 2.13.0, < 2.14.0"]}],"null_published_at":"2026-11-01T07:29:12.909Z","source_updated_at":"2026-09-29T23:43:20.000Z","source_disclosed_at":"2026-09-29T23:43:19.000Z","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":"2026-11-01T07:24:25.558Z"}],"next_cursor":null,"snapshot_revision":"42594"}