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CVE-2026-59884

CVE-2026-59884 · pyasn1 BER/CER/DER decoder denial of service via unbounded long-form tag IDs

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

pyasn1 is a generic ASN.1 library for Python. Prior to 0.6.4, the BER decoder shared by the CER and DER codecs parses long-form tags by accumulating continuation octets without an upper bound on the tag ID size, allowing a crafted input to force construction of an arbitrarily large integer with CPU cost growing quadratically and to trigger unhandled ValueError exceptions in Python 3.11+ error formatting paths. Any application decoding untrusted BER, CER, or DER input is affected. This issue is fixed in version 0.6.4.

CVSS 7.5 · High · EPSS 0.6% · Fix available

Published
Updated

Stack: system · python

Affected products and versions

  • pyasn1

    Versions
    • < 0.6.4: Affected

    No fix published

  • pyasn1 Debian:12

    Versions
    • 0.4.8-3
    • 0.4.8-3+deb12u1
    • 0.4.8-3+deb12u2
    Affected ranges
    • ECOSYSTEM: < 0.4.8-3+deb12u3

    Update to 0.4.8-3+deb12u3

  • pyasn1 Debian:13

    Versions
    • 0.6.1-1
    • 0.6.1-1+deb13u1
    • 0.6.1-1+deb13u2
    Affected ranges
    • ECOSYSTEM: < 0.6.1-1+deb13u3

    Update to 0.6.1-1+deb13u3

  • pyasn1 Debian:14

    Versions
    • 0.6.1-1
    • 0.6.2-1
    • 0.6.2-1~bpo13+1
    • 0.6.3-1
    • 0.6.4-1~bpo13+1
    Affected ranges
    • ECOSYSTEM: < 0.6.4-1

    Update to 0.6.4-1

  • pyasn1 PyPI

    Versions
    • 0.0.10a
    • 0.0.11a
    • 0.0.12a
    • 0.0.13
    • 0.0.13a
    • 0.0.13b
    • 0.0.6a
    • 0.0.9a
    • 0.1.1
    • 0.1.2
    • 0.1.3
    • 0.1.4
    • 0.1.5
    • 0.1.6
    • 0.1.7
    • 0.1.8
    • 0.1.9
    • 0.2.1
    • 0.2.2
    • 0.2.3
    • 0.3.1
    • 0.3.2
    • 0.3.3
    • 0.3.4
    • 0.3.5
    • 0.3.6
    • 0.3.7
    • 0.4.1
    • 0.4.2
    • 0.4.3
    • 0.4.4
    • 0.4.5
    • 0.4.6
    • 0.4.7
    • 0.4.8
    • 0.5.0
    • 0.5.1
    • 0.6.0
    • 0.6.1
    • 0.6.2
    • 0.6.3
    Affected ranges
    • ECOSYSTEM: < 0.6.4

    Update to 0.6.4

  • pyasn1 Ubuntu:Pro:14.04:LTS

    Versions
    • 0.1.4-0ubuntu1
    • 0.1.7-1ubuntu1
    • 0.1.7-1ubuntu2
    • 0.1.7-1ubuntu2.1
    • 0.1.7-1ubuntu2.1+esm1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • pyasn1 Ubuntu:Pro:16.04:LTS

    Versions
    • 0.1.8-2
    • 0.1.9-1
    • 0.1.9-1ubuntu0.1~esm1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • pyasn1 Ubuntu:Pro:18.04:LTS

    Versions
    • 0.1.9-2
    • 0.4.2-3
    • 0.4.2-3ubuntu0.18.04.1~esm1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • pyasn1 Ubuntu:Pro:20.04:LTS

    Versions
    • 0.4.2-3
    • 0.4.2-3build1
    • 0.4.2-3ubuntu0.20.04.1~esm1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • pyasn1 Ubuntu:22.04:LTS

    Versions
    • 0.4.8-1
    • 0.4.8-1ubuntu0.1
    • 0.4.8-1ubuntu0.2
    Affected ranges
    • ECOSYSTEM: < 0.4.8-1ubuntu0.3

    Update to 0.4.8-1ubuntu0.3

  • pyasn1 Ubuntu:24.04:LTS

    Versions
    • 0.4.8-4
    • 0.4.8-4ubuntu0.1
    • 0.4.8-4ubuntu0.2
    Affected ranges
    • ECOSYSTEM: < 0.4.8-4ubuntu0.3

    Update to 0.4.8-4ubuntu0.3

  • pyasn1 Ubuntu:26.04:LTS

    Versions
    • 0.6.1-1
    • 0.6.1-1build1
    • 0.6.2-1
    • 0.6.3-1
    Affected ranges
    • ECOSYSTEM: < 0.6.3-1ubuntu0.1

    Update to 0.6.3-1ubuntu0.1

Original sources

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