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CVE-2026-115352

CVE-2026-115352 · Mistune before 3.3.0 Quadratic-Time DoS via Unmatched Brackets in Inline Parser

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

Mistune before 3.3.0 contains an algorithmic complexity vulnerability in the inline link parser that allows unauthenticated attackers to exhaust CPU by submitting long runs of unmatched '[' characters. Attackers can send small markdown payloads that trigger O(N^2) parse_link_text and parse_link_label probing, occupying rendering workers for 30+ seconds per 16 KB input.

CVSS 8.7 · High · EPSS 0.4% · Fix available

Published
Updated

Stack: system

Affected products and versions

  • mistune

    Versions
    • ≥ 0, < 3.3.0: Affected (semver)
    • 3.3.0: Not affected (semver)

    Update to 3.3.0

  • mistune Debian:12

    Versions
    • 2.0.4-1
    • 2.0.4-2
    • 3.0.2-1
    • 3.0.2-2
    • 3.1.3-1
    • 3.1.4-1
    • 3.3.4-1
    • 3.4.0-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • mistune Debian:13

    Versions
    • 3.1.3-1
    • 3.1.4-1
    • 3.3.4-1
    • 3.4.0-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • mistune Debian:14

    Versions
    • 3.1.3-1
    • 3.1.4-1
    • 3.3.4-1
    • 3.4.0-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

Original sources

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