PyJWT.decode() reintroduces options-dict mutation, enabling silent claim-verification bypass on dict reuse (jpadilla pyjwt)
At a glance
- Source
- NVD
- EPSS
- EPSS 0.26 % · percentile 17 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- GitHub_M
- NVD status
- Analyzed
Description
PyJWT is a Python implementation of JSON Web Token standards. From 2.11.0 through 2.13.0, PyJWT's PyJWT._merge_options() method can modify a caller-supplied mutable options mapping when verify_signature is false. If an application reuses that same mapping for a later decode() or decode_complete() call and changes verify_signature to true, the mapping can retain false values for expiration, not-before, issued-at, audience, issuer, subject, and JWT ID checks. A signed token with invalid registered claims can then be accepted without disabling signature verification, but applications that create a fresh options mapping for each call are not affected.
Weaknesses (CWE)
- CWE-471 — Modification of Assumed-Immutable Data (MAID)
References
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | MEDIUM 6.5 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:N | GitHub_M |
| CVSS 3.1 | MEDIUM 6.5 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:N | NVD · security-advisories@github.com (Secondary) |
Advisories
- GHSA-gvp8-978c-rx2q — PyJWT.decode() reintroduces options-dict mutation, enabling silent claim-verification bypass on dict reuse
- PYSEC-2026-4146 — PyJWT.decode() reintroduces options-dict mutation, enabling silent claim-verification bypass on dict reuse
European references
- ENISA EUVD · EUVD-2026-90388
- GCVE · GCVE-0-2026-103001
CERT-FR advisories
- CERTFR-2026-AVI-1385 — Multiples vulnérabilités dans les produits VMware · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1249 — Multiples vulnérabilités dans les produits VMware · cert.ssi.gouv.fr
Affected configurations (NVD CPE)
cpe:2.3:a:pyjwt_project:pyjwt:*:*:*:*:*:*:*:*≥ 2.11.0 < 2.13.0
Affected products
| Product | Versions |
|---|---|
| jpadilla · pyjwt | affected >= 2.11.0, <= 2.13.0 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |