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CVE-2026-49854

CVE-2026-49854 · Tornado: Out-of-bounds memory access in C extension

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

Tornado is a Python web framework and asynchronous networking library. Prior to 6.5.6, the optional native extension tornado.speedups implemented websocket_mask without validating that the mask argument is exactly four bytes, allowing the C function to read up to three bytes beyond the provided buffer when reached through Tornado XSRF token decoding with the native extension active. This issue is fixed in version 6.5.6.

CVSS 5.3 · Medium · EPSS 0.4% · Fix available

Published
Updated

Stack: system · python

Affected products and versions

  • tornado

    Versions
    • < 6.5.6: Affected

    No fix published

  • python-tornado Debian:12

    Versions
    • 6.2.0-3
    • 6.2.0-3+deb12u1
    • 6.2.0-3+deb12u2
    • 6.2.0-3+deb12u3
    • 6.2.0-3+deb12u4
    • 6.3.2-1
    • 6.4.0-1
    • 6.4.0-2
    • 6.4.1-1
    • 6.4.1-2
    • 6.4.1-3
    • 6.4.2-1
    • 6.4.2-2
    • 6.4.2-3
    • 6.5.2-1
    • 6.5.2-2
    • 6.5.2-3
    • 6.5.4-0.1
    • 6.5.4-1
    • 6.5.5-1
    • 6.5.5-2
    • 6.5.5-3
    • 6.5.5-4
    • 6.5.5-5
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • python-tornado Debian:13

    Versions
    • 6.4.2-3
    • 6.4.2-3+deb13u1
    • 6.4.2-3+deb13u2
    • 6.5.2-1
    • 6.5.2-2
    • 6.5.2-3
    • 6.5.4-0.1
    • 6.5.4-1
    • 6.5.5-1
    • 6.5.5-2
    • 6.5.5-3
    • 6.5.5-4
    • 6.5.5-5
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • python-tornado Debian:14

    Versions
    • 6.4.2-3
    • 6.5.2-1
    • 6.5.2-2
    • 6.5.2-3
    • 6.5.4-0.1
    • 6.5.4-1
    • 6.5.5-1
    • 6.5.5-2
    • 6.5.5-3
    • 6.5.5-4
    • 6.5.5-5
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • tornado PyPI

    Versions
    • 0.2
    • 1.0
    • 1.1
    • 1.1.1
    • 1.2
    • 1.2.1
    • 2.0
    • 2.1
    • 2.1.1
    • 2.2
    • 2.2.1
    • 2.3
    • 2.4
    • 2.4.1
    • 3.0
    • 3.0.1
    • 3.0.2
    • 3.1
    • 3.1.1
    • 3.2
    • 3.2.1
    • 3.2.2
    • 4.0
    • 4.0.1
    • 4.0.2
    • 4.1
    • 4.1b2
    • 4.2
    • 4.2.1
    • 4.2b1
    • 4.3
    • 4.3b1
    • 4.3b2
    • 4.4
    • 4.4.1
    • 4.4.2
    • 4.4.3
    • 4.4b1
    • 4.5
    • 4.5.1
    • 4.5.2
    • 4.5.3
    • 4.5b1
    • 4.5b2
    • 5.0
    • 5.0.1
    • 5.0.2
    • 5.0a1
    • 5.0b1
    • 5.1
    • 5.1.1
    • 5.1b1
    • 6.0
    • 6.0.1
    • 6.0.2
    • 6.0.3
    • 6.0.4
    • 6.0a1
    • 6.0b1
    • 6.1
    • 6.1b1
    • 6.1b2
    • 6.2
    • 6.2b1
    • 6.2b2
    • 6.3
    • 6.3.1
    • 6.3.2
    • 6.3.3
    • 6.3b1
    • 6.4
    • 6.4.1
    • 6.4.2
    • 6.4b1
    • 6.5
    • 6.5.1
    • 6.5.2
    • 6.5.3
    • 6.5.4
    • 6.5.5
    • 6.5b1
    Affected ranges
    • ECOSYSTEM: < 6.5.6

    Update to 6.5.6

  • python-tornado Ubuntu:Pro:16.04:LTS

    Versions
    • 4.2.1-1ubuntu2
    • 4.2.1-1ubuntu3
    • 4.2.1-1ubuntu3.1
    • 4.2.1-1ubuntu3.1+esm1
    • 4.2.1-1ubuntu3.1+esm2
    • 4.2.1-1ubuntu3.1+esm3
    • 4.2.1-1ubuntu3.1+esm4
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • python-tornado Ubuntu:Pro:18.04:LTS

    Versions
    • 4.5.1-2.1~build2
    • 4.5.2-1
    • 4.5.3-1
    • 4.5.3-1ubuntu0.1
    • 4.5.3-1ubuntu0.2
    • 4.5.3-1ubuntu0.2+esm1
    • 4.5.3-1ubuntu0.2+esm2
    • 4.5.3-1ubuntu0.2+esm3
    • 4.5.3-1ubuntu0.2+esm4
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • python-tornado Ubuntu:Pro:20.04:LTS

    Versions
    • 5.1.1-4ubuntu1
    • 5.1.1-4ubuntu5
    • 6.0.3+really5.1.1-2
    • 6.0.3+really5.1.1-2build1
    • 6.0.3+really5.1.1-2build2
    • 6.0.3+really5.1.1-3
    • 6.0.3+really5.1.1-3ubuntu0.1~esm1
    • 6.0.3+really5.1.1-3ubuntu0.1~esm3
    • 6.0.3+really5.1.1-3ubuntu0.1~esm5
    • 6.0.3+really5.1.1-3ubuntu0.1~esm7
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • python-tornado Ubuntu:Pro:22.04:LTS

    Versions
    • 6.1.0-1build1
    • 6.1.0-2
    • 6.1.0-3
    • 6.1.0-3build1
    • 6.1.0-3ubuntu0.1~esm1
    • 6.1.0-3ubuntu0.1~esm2
    • 6.1.0-3ubuntu0.1~esm4
    • 6.1.0-3ubuntu0.1~esm5
    • 6.1.0-3ubuntu0.1~esm6
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • python-tornado Ubuntu:24.04:LTS

    Versions
    • 6.3.2-1
    • 6.4.0-0ubuntu1
    • 6.4.0-1
    • 6.4.0-1build1
    • 6.4.0-1ubuntu0.1
    • 6.4.0-1ubuntu0.2
    • 6.4.0-1ubuntu0.4
    • 6.4.0-1ubuntu0.5
    • 6.4.0-1ubuntu0.6
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • python-tornado Ubuntu:26.10

    Versions
    • 6.5.4-0.1
    • 6.5.5-2
    • 6.5.5-4
    • 6.5.5-5
    • 6.5.5-5ubuntu1.1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • python-tornado Ubuntu:26.04:LTS

    Versions
    • 6.4.2-3
    • 6.5.2-3
    • 6.5.4-0.1
    • 6.5.4-0.1ubuntu0.1
    • 6.5.4-0.1ubuntu0.2
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

Original sources

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