CVE-2026-48526

PyJWT: Public-key JWK accepted as HMAC secret enables forged HS256 tokens when mixed families are allowed

HIGH 7.4

At a glance

Source
NVD
EPSS
EPSS 0.43 % · percentile 37 ()
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.

Weaknesses (CWE)

  • CWE-287 — Improper Authentication
  • CWE-347 — Improper Verification of Cryptographic Signature

References

Scores

VersionScoreVectorScored by
CVSS 3.1HIGH 7.4CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:NGitHub_M
CVSS 3.1HIGH 7.4CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:Nredhat-SADP
CVSS 3.1HIGH 7.4CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:NNVD · security-advisories@github.com (Secondary)
CVSS 3.1HIGH 7.4CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:NNVD · 0b0ca135-0b70-47e7-9f44-1890c2a1c46c (Secondary)

Advisories

European references

CERT-FR advisories

Affected configurations (NVD CPE)

Affected products

ProductVersions
jpadilla · pyjwtaffected < 2.13.0

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
EPSS (FIRST.org)FIRST — attribution requested
ENISA EUVDENISA — reproduction authorised, source acknowledged
CERT-FR (ANSSI)Licence Ouverte / Etalab 2.0
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain — this product uses data from the NVD API but is not endorsed or certified by the NVD