CVE-2026-86428 commonmark 1.5.0 before 2.10.0 Denial of Service via Attributes

commonmark versions from 1.5.0 before 2.10.0 contain a denial of service vulnerability in the AttributesExtension when processing distinctly-named attributes. Attackers can submit Markdown with numerous distinct attribute names to cause quadratic-time attribute merging and filtering, consuming...

EUVD-2026-72386

commonmark versions from 1.5.0 before 2.10.0 contain a denial of service vulnerability in the AttributesExtension when processing distinctly-named attributes. Attackers can submit Markdown with numerous distinct attribute names to cause quadratic-time attribute merging and filtering, consuming...

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 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-2026-86428 commonmark 1.5.0 before 2.10.0 Denial of Service via Attributes

commonmark versions from 1.5.0 before 2.10.0 contain a denial of service vulnerability in the AttributesExtension when processing distinctly-named attributes. Attackers can submit Markdown with numerous distinct attribute names to cause quadratic-time attribute merging and filtering, consuming...

EUVD-2026-72387

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-2026-86431: Improper Neutralization of Input During Web Page Generation

league/commonmark thephpleague/commonmark versions = 2.7.0 and 2.9.1 contain a cross-site scripting vulnerability in the AttributesExtension. Prefixing an attribute name with a single U+000C form feed byte e.g. \x0Conclick="alert1" bypasses the AttributesHelper::filterAttributes 'on' event-handle...

CVE-2026-86429: Inefficient Algorithmic Complexity

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...

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...

Linux Distros Unpatched Vulnerability : CVE-2026-86434

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available. - league/commonmark versions = 2.0.0 and 2.8.4 patched in 2.9.0 contain a denial of service vulnerability in UniqueSlugNormalizer::normalize, which restarts its...

Linux Distros Unpatched Vulnerability : CVE-2026-86432

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 2.0.0 before 2.8.4 contain a denial of service vulnerability in XmlRenderer that emits depth-proportional indentation for every XML tag...

CVE-2026-86428: Inefficient Algorithmic Complexity

commonmark versions from 1.5.0 before 2.10.0 contain a denial of service vulnerability in the AttributesExtension when processing distinctly-named attributes. Attackers can submit Markdown with numerous distinct attribute names to cause quadratic-time attribute merging and filtering, consuming...

PT-2026-86801

commonmark versions from 1.5.0 before 2.8.4 contain a denial of service vulnerability in the Footnote extension that fails to deduplicate footnote definitions. Attackers can craft documents with duplicate footnote definitions and references to create quadratic output expansion, consuming excessiv...

CVE-2026-86434: Inefficient Algorithmic Complexity

league/commonmark versions = 2.0.0 and 2.8.4 patched in 2.9.0 contain a denial of service vulnerability in UniqueSlugNormalizer::normalize, which restarts its numeric-suffix search from 1 on every slug collision, resulting in OK^2 time complexity for K headings that collapse to the same base slug...

PT-2026-86800

Name of the Vulnerable Software and Affected Versions league/commonmark versions 2.0.0 through 2.8.3 Description A denial of service issue exists in the UniqueSlugNormalizer::normalize function. The problem occurs when the function restarts its numeric-suffix search from 1 during every slug...

Linux Distros Unpatched Vulnerability : CVE-2026-86435

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 Footnote extension that fails to deduplicate footnote definitions...

CVE-2026-86430: Inefficient Algorithmic Complexity

league/commonmark versions before 2.9.1 contain multiple denial of service vulnerabilities in fenced code block detection, reference link label lookup, and emphasis delimiter processing that perform super-linear work on crafted input. Attackers can submit specially crafted Markdown with long...

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...

PT-2026-86797

league/commonmark thephpleague/commonmark versions = 2.7.0 and 2.9.1 contain a cross-site scripting vulnerability in the AttributesExtension. Prefixing an attribute name with a single U+000C form feed byte e.g. x0Conclick="alert1" bypasses the AttributesHelper::filterAttributes 'on' event-handler...

CVE-2026-86435: Inefficient Algorithmic Complexity

commonmark versions from 1.5.0 before 2.8.4 contain a denial of service vulnerability in the Footnote extension that fails to deduplicate footnote definitions. Attackers can craft documents with duplicate footnote definitions and references to create quadratic output expansion, consuming excessiv...