PyJWT is a Python implementation of JSON Web Token standards. From 2.13.0 until 2.14.0, HMACAlgorithm.prepare_key in jwt/algorithms.py is affected because raw-JWK detector does not normalize accepted Unicode byte-order marks before checking for JSON. This occurs when a public JWK is prefixed with a UTF-8 BOM and used in a mixed-algorithm verification path. As a result, public JWK bypasses asymmetric-key detection and becomes the HMAC secret. Consequently, an attacker who knows the public key can forge authenticated tokens. This issue is fixed in version 2.14.0.
CVE-2026-102272
This high-severity CVE scores 7.4 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.2% (7th percentile of EPSS-scored CVEs). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
- High severity, but no confirmed exploitation yet
A fix is available — apply it.
- CVSS v3
- 7.4
- EG Score
- 7.4HIGHmedium confidence
- EG Risk
- 49EG Risk 49/100CISA SSVC
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity74% × 45%Exploitation40% × 40%Automatability0% × 15%CISA SSVC: Track at low, Track* at medium and Attend at high mission impact.Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high. - EPSS PROB
- 0.2%
- EPSS %ILE
- 7th
- KEV
- Not listed
CISA SSVCTrack at low, Track* at medium and Attend at high mission impact.
A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
Exploitation public PoC (CISA Vulnrichment) · Automatable no (CISA Vulnrichment) · Technical impact total (CISA Vulnrichment). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table
Published
September 28, 2026
Last Modified
September 30, 2026
Advisory Details (3)
Auto-updated Sep 28, 20262.14.0
Patch available: jpadilla/pyjwt 2.14.0
https://github.com/jpadilla/pyjwt/releases/tag/2.14.0commit 180783930de9 (jpadilla/pyjwt)
Patch available: jpadilla/pyjwt 2.14.0 (contains commit 180783930de9)
https://github.com/jpadilla/pyjwt/commit/180783930de91876bc0d601f826a1f2956057291PyJWT 2.13.0 BOM Bypass · Advisory · jpadilla/pyjwt · GitHub
https://github.com/jpadilla/pyjwt/security/advisories/GHSA-r6x4-923q-g947Vendor Advisories for CVE-2026-102272(2)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Affected Packages
(1 across 1 ecosystem)
PyPI(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| pyjwt | 2.13.0 | 2.14.0 | — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 21× in last 7d / 21× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-10-04 11:47 UTCVendor advisory
- 2026-10-04 00:50 UTCEG score recompute
- 2026-10-04 00:50 UTCVendor advisory
- 2026-10-03 14:25 UTCEPSS rescore
- 2026-10-03 13:54 UTCVendor advisory
- 2026-10-03 02:55 UTCEG score recompute
- 2026-10-03 02:55 UTCVendor advisory
- 2026-10-02 15:57 UTCVendor advisory
- 2026-10-02 04:59 UTCEG score recompute
- 2026-10-02 04:59 UTCVendor advisory
- 2026-10-01 19:49 UTCEPSS rescore
- 2026-10-01 18:00 UTCVendor advisory
- 2026-09-30 20:02 UTCEG score recompute
- 2026-09-30 15:02 UTCEPSS rescore
- 2026-09-29 15:24 UTCEG score recompute
- 2026-09-29 15:20 UTCEPSS rescore
- 2026-09-29 14:49 UTCEG score recompute
- 2026-09-29 08:15 UTCEG score recompute
- 2026-09-28 21:18 UTCEG score recompute
- 2026-09-28 20:46 UTCEG score recompute
- 2026-09-28 20:46 UTCMITRE cvelistV5first tracked
Related CVEs(same product + same CWE)
Same product
10 shownPyPI:pyjwt
Frequently asked(5)
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Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-102272
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