CVE-2026-103001 — PyJWT.decode() reintroduces options-dict mutation, enabling silent claim-verification bypass on dict reuse
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 mapp…
Published: 2026-09-30 · CVSS: 6.5 · CVSS 3.1
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.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7