PyJWT.decode() reintroduces options-dict mutation, enabling silent claim-verification bypass on dict reuse

SummaryPyJWT.decode/decodecomplete mutates a caller-supplied options dict in place whenever verifysignature is falsy, adding verifyexp/verifynbf/verifyiat/verifyaud/verifyiss/verifysub/verifyjti keys directly onto that object. If application code reuses the same options dict across calls a config...

PYSEC-2026-4146 PyJWT.decode() reintroduces options-dict mutation, enabling silent claim-verification bypass on dict reuse

Summary PyJWT.decode/decodecomplete mutates a caller-supplied options dict in place whenever verifysignature is falsy, adding verifyexp/verifynbf/verifyiat/verifyaud/verifyiss/verifysub/verifyjti keys directly onto that object. If application code reuses the same options dict across calls a confi...

GHSA-GVP8-978C-RX2Q PyJWT.decode() reintroduces options-dict mutation, enabling silent claim-verification bypass on dict reuse

Summary PyJWT.decode/decodecomplete mutates a caller-supplied options dict in place whenever verifysignature is falsy, adding verifyexp/verifynbf/verifyiat/verifyaud/verifyiss/verifysub/verifyjti keys directly onto that object. If application code reuses the same options dict across calls a confi...

PyJWT.decode() reintroduces options-dict mutation, enabling silent claim-verification bypass on dict reuse

Summary PyJWT.decode/decodecomplete mutates a caller-supplied options dict in place whenever verifysignature is falsy, adding verifyexp/verifynbf/verifyiat/verifyaud/verifyiss/verifysub/verifyjti keys directly onto that object. If application code reuses the same options dict across calls a confi...

CVE-2026-103001

The PyJWT library (versions 2.11.0 through 2.13.0 ) contains a vulnerability where the PyJWT._merge_options() method modifies a caller-supplied mutable options mapping when verify_signature is set to false . If an application reuses this same mapping for subsequent decode() or decode_complete() c...

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.mergeoptions method can modify a caller-supplied mutable options mapping when verifysignature is false. If an application reuses that same mapping for a later decode or decodecomplete call and...