CVE-2026-48526
PyJWT: Public-key JWK accepted as HMAC secret enables forged HS256 tokens when mixed families are allowed
At a glance
- Severity
- HIGH 7.4
- EPSS
- EPSS 0.43 % · percentile 37 (2026-10-27)
- State
- PUBLISHED
- Published
- Updated
- Assigner
- GitHub_M
- NVD status
- Modified
Description
PyJWT is a JSON Web Token implementation in Python. Prior to 2.13.0, when the verifier is decoding JSON Web Tokens, while supporting both asymmetric and HMAC algorithms, the library does not validate use of JSON Web Keys in HMAC algorithm, allowing attacker to use the issuer public key as the secret key for HMAC algorithm. This vulnerability is fixed in 2.13.0.
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | HIGH 7.4 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N | GitHub_M |
| CVSS 3.1 | HIGH 7.4 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N | redhat-SADP |
| CVSS 3.1 | HIGH 7.4 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N | NVD · security-advisories@github.com (Secondary) |
| CVSS 3.1 | HIGH 7.4 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N | NVD · 0b0ca135-0b70-47e7-9f44-1890c2a1c46c (Secondary) |
Weaknesses (CWE)
Advisories
- GHSA-xgmm-8j9v-c9wx — PyJWT: Public-key JWK accepted as HMAC secret enables forged HS256 tokens when mixed families are allowed
- PYSEC-2026-179 — PyJWT is a JSON Web Token implementation in Python. Prior to 2.13.0, when the verifier is decoding JSON Web Tokens, while supporting both asymmetric and HMAC al
European references
- ENISA EUVD · EUVD-2026-32917
- GCVE · GCVE-0-2026-48526
CERT-FR advisories
- CERTFR-2026-AVI-1385 — Multiples vulnérabilités dans les produits VMware · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1366 — Multiples vulnérabilités dans les produits Splunk · cert.ssi.gouv.fr
Affected configurations (NVD CPE)
cpe:2.3:a:pyjwt_project:pyjwt:*:*:*:*:*:*:*:*< 2.13.0
Affected products
| Product | Versions |
|---|---|
| jpadilla · pyjwt | affected < 2.13.0 |
References
- https://github.com/jpadilla/pyjwt/security/advisories/GHSA-xgmm-8j9v-c9wx
- https://access.redhat.com/security/cve/CVE-2026-48526
- https://bugzilla.redhat.com/show_bug.cgi?id=2482734
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-48526.json
- https://access.redhat.com/errata/RHSA-2026:50319
- https://access.redhat.com/errata/RHSA-2026:50223
- https://access.redhat.com/errata/RHSA-2026:50336
- https://access.redhat.com/errata/RHSA-2026:34160
- https://access.redhat.com/errata/RHSA-2026:50222
- https://access.redhat.com/errata/RHSA-2026:50263
- https://access.redhat.com/errata/RHSA-2026:34365
- https://access.redhat.com/errata/RHSA-2026:35845
- https://access.redhat.com/errata/RHSA-2026:25902
- https://access.redhat.com/errata/RHSA-2026:35837
- https://access.redhat.com/errata/RHSA-2026:35836
- https://access.redhat.com/errata/RHSA-2026:35835
- https://access.redhat.com/errata/RHSA-2026:26206
- https://access.redhat.com/errata/RHSA-2026:30089
- https://access.redhat.com/errata/RHSA-2026:30088
- https://access.redhat.com/errata/RHSA-2026:42144
- https://access.redhat.com/errata/RHSA-2026:42132
- https://access.redhat.com/errata/RHSA-2026:34374
- https://access.redhat.com/errata/RHSA-2026:50340
- https://access.redhat.com/errata/RHSA-2026:25928
- https://access.redhat.com/errata/RHSA-2026:42142
- https://access.redhat.com/errata/RHSA-2026:43038
- https://access.redhat.com/errata/RHSA-2026:42644
- https://access.redhat.com/errata/RHSA-2026:37275
- https://access.redhat.com/errata/RHSA-2026:60520
- https://access.redhat.com/errata/RHSA-2026:33683
- https://access.redhat.com/errata/RHSA-2026:30076
- https://access.redhat.com/errata/RHSA-2026:42796
- https://access.redhat.com/errata/RHSA-2026:41066
- https://access.redhat.com/errata/RHSA-2026:48085
- https://access.redhat.com/errata/RHSA-2026:28571
- https://access.redhat.com/errata/RHSA-2026:36350
- https://access.redhat.com/errata/RHSA-2026:40967
- https://access.redhat.com/errata/RHSA-2026:50904
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 |