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CVE-2026-48990

CVE-2026-48990 · joserfc: b64=false RFC7797 JWS payloads bypass JWSRegistry payload-size limits during deserialization

This page contains facts from public vulnerability sources. Check the original advisory before updating.

joserfc is a Python library that provides an implementation of several JSON Object Signing and Encryption (JOSE) standards. In versions 1.3.4 through 1.6.5, joserfc accepts oversized RFC7797 b64=false JWS payloads without applying JWSRegistry.max_payload_length, which can lead to resource exhaustion. The normal JWS compact and flattened JSON paths reject payloads above the configured payload-size limit with ExceededSizeError. The RFC7797 unencoded payload paths do not make the same check. A valid b64=false compact or flattened JSON JWS can therefore deserialize successfully with a payload larger than JWSRegistry.max_payload_length. Applications that accept lower-trust JWS values and rely on joserfc to reject oversized token content during verification have a moderate availability risk. This issue has been fixed in version 1.6.7.

CVSS 5.3 · Medium · EPSS 0.3% · Fix available

Published
Updated

Stack: system · python

Affected products and versions

  • joserfc

    Versions
    • < 1.6.7: Affected

    No fix published

  • joserfc Debian:13

    Versions
    • 1.1.0-1
    • 1.2.0-1
    • 1.2.2-1
    • 1.3.1-1
    • 1.3.2-1
    • 1.3.4-1
    • 1.4.0-1
    • 1.4.1-1
    • 1.4.3-1
    • 1.5.0-1
    • 1.6.0-1
    • 1.6.1-1
    • 1.6.2-1
    • 1.6.3-1
    • 1.6.4-1
    • 1.6.5-1
    • 1.6.8-1
    • 1.7.0-1
    • 1.7.1-1
    • 1.7.2-1
    • 1.7.3-1
    • 1.7.4-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • joserfc Debian:14

    Versions
    • 1.1.0-1
    • 1.2.0-1
    • 1.2.2-1
    • 1.3.1-1
    • 1.3.2-1
    • 1.3.4-1
    • 1.4.0-1
    • 1.4.1-1
    • 1.4.3-1
    • 1.5.0-1
    • 1.6.0-1
    • 1.6.1-1
    • 1.6.2-1
    • 1.6.3-1
    • 1.6.4-1
    • 1.6.5-1
    Affected ranges
    • ECOSYSTEM: < 1.6.8-1

    Update to 1.6.8-1

  • joserfc PyPI

    Versions
    • 1.3.4
    • 1.3.5
    • 1.4.0
    • 1.4.1
    • 1.4.2
    • 1.4.3
    • 1.5.0
    • 1.6.0
    • 1.6.1
    • 1.6.2
    • 1.6.3
    • 1.6.4
    • 1.6.5
    Affected ranges
    • ECOSYSTEM: ≥ 1.3.4, < 1.6.7

    Update to 1.6.7

  • joserfc Ubuntu:25.10

    Versions
    • 1.0.4-1
    • 1.1.0-1
    • 1.2.0-1
    • 1.2.2-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • joserfc Ubuntu:26.04:LTS

    Versions
    • 1.2.2-1
    • 1.4.0-1
    • 1.4.1-1
    • 1.4.3-1
    • 1.5.0-1
    • 1.6.2-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

Original sources

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