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-2026-86432 commonmark 2.0.0 before 2.8.4 Denial of Service via XML

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. Attackers can provide deeply nested Markdown or AST structures to cause quadratic memory consumption and output amplification, exhausti...

CVE-2026-86431 commonmark before 2.9.1 XSS via AttributesExtension form feed bypass

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-2026-86431

league/commonmark (thephpleague/commonmark) versions >= 2.7.0 and

EUVD-2026-72389

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-2026-86431

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-2026-86432

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. Attackers can provide deeply nested Markdown or AST structures to cause quadratic memory consumption and output amplification, exhausti...

CVE-2026-86432

commonmark (versions 2.0.0 through before 2.8.4) contains a denial of service vulnerability in its XmlRenderer component. The root cause is that the renderer emits depth-proportional indentation for every XML tag, so deeply nested Markdown or AST structures trigger quadratic memory consumption an...

CVE-2026-86431 commonmark before 2.9.1 XSS via AttributesExtension form feed bypass

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...

EUVD-2026-72390

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. Attackers can provide deeply nested Markdown or AST structures to cause quadratic memory consumption and output amplification, exhausti...

EUVD-2026-72388

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...

CVE-2026-86430 league/commonmark before 2.9.1 Denial of Service via parsing

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...

CVE-2026-86430

league/commonmark (a PHP Markdown parsing library) versions before 2.9.1 are affected by multiple denial-of-service vulnerabilities in three components: fenced code block detection , reference link label lookup , and emphasis delimiter processing . The root cause is super-linear work performed on...

CVE-2026-86430 league/commonmark before 2.9.1 Denial of Service via parsing

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...

CVE-2026-86430

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...

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

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 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-2026-86428

PHP League CommonMark (versions 1.5.0 through before 2.10.0 ) is affected by a denial-of-service vulnerability in the AttributesExtension . When processing Markdown containing numerous distinctly-named attributes, the extension performs quadratic-time attribute merging and filtering , consuming d...