Inefficient Algorithmic Complexity

Overview league/commonmark is a PHP-based Markdown parser which supports the full CommonMark spec. It is based on the CommonMark JS reference implementation. Affected versions of this package are vulnerable to Inefficient Algorithmic Complexity through the AttributesListener::findTargetAndDirecti...

DEBIAN-CVE-2026-86433

commonmark versions from 1.5.0 before 2.8.4 contain a denial of service vulnerability in the Attributes extension where AttributesListener::findTargetAndDirection performs quadratic-time sibling list scanning. Unauthenticated attackers can submit approximately 32 KB of repeated attribute blocks t...

CVE-2026-86433

commonmark versions from 1.5.0 before 2.8.4 contain a denial of service vulnerability in the Attributes extension where AttributesListener::findTargetAndDirection performs quadratic-time sibling list scanning. Unauthenticated attackers can submit approximately 32 KB of repeated attribute blocks t...

CVE-2026-86433 commonmark 1.5.0 before 2.8.4 Denial of Service via Attributes

commonmark versions from 1.5.0 before 2.8.4 contain a denial of service vulnerability in the Attributes extension where AttributesListener::findTargetAndDirection performs quadratic-time sibling list scanning. Unauthenticated attackers can submit approximately 32 KB of repeated attribute blocks t...

CVE-2026-86433 commonmark 1.5.0 before 2.8.4 Denial of Service via Attributes

commonmark versions from 1.5.0 before 2.8.4 contain a denial of service vulnerability in the Attributes extension where AttributesListener::findTargetAndDirection performs quadratic-time sibling list scanning. Unauthenticated attackers can submit approximately 32 KB of repeated attribute blocks t...

EUVD-2026-72391

commonmark versions from 1.5.0 before 2.8.4 contain a denial of service vulnerability in the Attributes extension where AttributesListener::findTargetAndDirection performs quadratic-time sibling list scanning. Unauthenticated attackers can submit approximately 32 KB of repeated attribute blocks t...

CVE-2026-86433

commonmark (PHP Markdown parser) versions 1.5.0 through 2.8.3 contain a denial-of-service vulnerability in the Attributes extension . The root cause is that AttributesListener::findTargetAndDirection() performs quadratic-time sibling list scanning , allowing an unauthenticated attacker to submit ...

CVE-2026-86429 commonmark before 2.9.1 Denial of Service via SmartPunct and Attributes

The league/commonmark thephpleague/commonmark library in versions = 1.5.0 and 2.9.1 contains quadratic parsing complexity in its SmartPunctExtension and AttributesExtension. When either extension is explicitly registered on the Environment they are not enabled by default and are excluded from the...

CVE-2026-86429

CVE-2026-86429 affects the thephpleague/commonmark PHP library (versions ≥ 1.5.0,

PT-2026-86799

commonmark versions from 1.5.0 before 2.8.4 contain a denial of service vulnerability in the Attributes extension where AttributesListener::findTargetAndDirection performs quadratic-time sibling list scanning. Unauthenticated attackers can submit approximately 32 KB of repeated attribute blocks t...

Linux Distros Unpatched Vulnerability : CVE-2026-86433

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available. - commonmark versions from 1.5.0 before 2.8.4 contain a denial of service vulnerability in the Attributes extension where AttributesListener::findTargetAndDirecti...

CVE-2026-86433: Inefficient Algorithmic Complexity

commonmark versions from 1.5.0 before 2.8.4 contain a denial of service vulnerability in the Attributes extension where AttributesListener::findTargetAndDirection performs quadratic-time sibling list scanning. Unauthenticated attackers can submit approximately 32 KB of repeated attribute blocks t...

GHSA-8RR7-CVQ3-GMFH league/commonmark: Denial of service via distinctly-named attributes in the Attributes extension

Impact AttributesExtension ships with the library but must be explicitly registered on the Environment; it is not included in CommonMarkConverter, GithubFlavoredMarkdownConverter, or GithubFlavoredMarkdownExtension. Applications that do not register AttributesExtension are not affected by this...

CVE-2026-71478

league/commonmark is a PHP library for parsing and rendering CommonMark Markdown. From 1.5.0 until 2.9.0, the AttributesExtension's href and src unsafe-link filter can be bypassed by embedding control bytes, such as a tab, carriage return, line feed, or leading C0 control character, in a...

UBUNTU-CVE-2026-71478

league/commonmark is a PHP library for parsing and rendering CommonMark Markdown. From 1.5.0 until 2.9.0, the AttributesExtension's href and src unsafe-link filter can be bypassed by embedding control bytes, such as a tab, carriage return, line feed, or leading C0 control character, in a...

Inefficient Algorithmic Complexity

Overview league/commonmark is a PHP-based Markdown parser which supports the full CommonMark spec. It is based on the CommonMark JS reference implementation. Affected versions of this package are vulnerable to Inefficient Algorithmic Complexity due to inefficient processing in the...

league/commonmark: AttributesExtension href/src unsafe-link filter bypass via embedded control bytes

Summary The AttributesExtension's href/src unsafe-link filter AttributesHelper::filterAttributes can be bypassed by embedding control bytes in a javascript: URL that browsers discard before parsing the scheme. Two variants: - Tab/newline inside the scheme — a literal ASCII TAB 0x09, CR 0x0D, or...

GHSA-29PJ-957V-52MC league/commonmark: AttributesExtension href/src unsafe-link filter bypass via embedded control bytes

Summary The AttributesExtension's href/src unsafe-link filter AttributesHelper::filterAttributes can be bypassed by embedding control bytes in a javascript: URL that browsers discard before parsing the scheme. Two variants: - Tab/newline inside the scheme — a literal ASCII TAB 0x09, CR 0x0D, or...

CVE-2026-71478

league/commonmark is a PHP library for parsing and rendering CommonMark Markdown. From 1.5.0 until 2.9.0, the AttributesExtension's href and src unsafe-link filter can be bypassed by embedding control bytes, such as a tab, carriage return, line feed, or leading C0 control character, in a...

CVE-2026-71478 league/commonmark: AttributesExtension href/src unsafe-link filter bypass via embedded control bytes

league/commonmark is a PHP library for parsing and rendering CommonMark Markdown. From 1.5.0 until 2.9.0, the AttributesExtension's href and src unsafe-link filter can be bypassed by embedding control bytes, such as a tab, carriage return, line feed, or leading C0 control character, in a...