CVE-2026-102273
validatedZero produced an exploit or a check.GHSA-w2cx-738m-mc7w ↗EUVD-2026-88541 ↗
description
PyJWT 2.13.0 can mishandle public-key material stored in JWK container formats during HMAC JWT verification. An attacker with the public key may create tokens carrying attacker-chosen authenticated claims when the application mixes HMAC and asymmetric algorithms and reuses raw public JWK or JWKS data as an HMAC key.
mitigation
Upgrade PyJWT to version 2.14.0 or later. Keep symmetric and asymmetric verification flows separate, and do not use public JWK or JWKS data as an HMAC secret.
fixed in 2.14.0
outcome
Mechanism verified: the exploit fired on the vulnerable build and stayed silent on the patched one, but the server it ran against was ours, so no check ships for it.
source signals
Public signals that triggered or updated the pipeline. These are inputs for the deltas above.
- 2026-09-28 20:38Zghsa: trigger signal, started the run
- 2026-09-28 20:38Zcve.org record for CVE-2026-102273
this entry in the feed
GET /api/v1/feed/CVE-2026-102273
{ "etk_id": "ETK-2026-14", "cve_id": "CVE-2026-102273", "display_id": "CVE-2026-102273", "ghsa_id": "GHSA-w2cx-738m-mc7w", "euvd_id": "EUVD-2026-88541", "status": "published", "anchor_state": "anchored", "title": "Algorithm-confusion token forgery in PyJWT HMAC key handling", "summary": "PyJWT 2.13.0 can mishandle public-key material stored in JWK container formats during HMAC JWT verification. An attacker with the public key may create tokens carrying attacker-chosen authenticated claims when the application mixes HMAC and asymmetric algorithms and reuses raw public JWK or JWKS data as an HMAC key.", "mitigation": "Upgrade PyJWT to version 2.14.0 or later. Keep symmetric and asymmetric verification flows separate, and do not use public JWK or JWKS data as an HMAC secret.", "vendor": "pip", "product": "pip:PyJWT", "affected": [ { "affected_notes": [], "affected_ranges": [ "= 2.13.0" ], "ecosystem": "pip", "fixed_versions": [ "2.14.0" ], "package_name": "PyJWT", "purl": "pkg:pypi/PyJWT" } ], "cwes": [ 347 ], "cvss_score": 7.4, "cvss_src": "cna_vendor", "cvss_vector": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N", "epss_score": 0.0018, "epss_percentile": 0.0655, "epss_asof": "2026-10-20", "automation": "contextual", "check": true, "check_confidence_basis": "mechanism_verified", "exploit": false, "pipeline_minutes": 11.581535066666667, "t0_at": "2026-09-28T20:38:28.161000+00:00", "signals": { "check": { "at": "2026-09-29T21:05:22.842607+00:00", "days": 1.018688444525463, "is_lower_bound": false, "measured_at": "2026-09-28T20:38:28.161000+00:00", "url": null }, "trigger_signal": { "at": "2026-09-28T20:38:28.161000+00:00", "days": 0, "is_lower_bound": false, "measured_at": "2026-09-28T20:38:28.161000+00:00", "url": "https://github.com/jpadilla/pyjwt/security/advisories/GHSA-w2cx-738m-mc7w" } } }
published 2026-09-29 20:53Z
last change 2026-10-21 06:02Z
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