Mistune: Denial of Service — RecursionError via Excessive Emphasis Markers in Markdown

SummaryMistune v3.3.2 is vulnerable to a Denial of Service DoS attack via uncontrolled recursion in the HTML rendering of deeply-nested emphasis tokens. By submitting Markdown containing approximately 1,000 consecutive asterisk characters, an attacker causes the Python process to crash with...

PYSEC-2026-3863 Mistune: Denial of Service — RecursionError via Excessive Emphasis Markers in Markdown

Summary Mistune v3.3.2 is vulnerable to a Denial of Service DoS attack via uncontrolled recursion in the HTML rendering of deeply-nested emphasis tokens. By submitting Markdown containing approximately 1,000 consecutive asterisk characters, an attacker causes the Python process to crash with...

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...

DEBIAN-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-2026-72388

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 (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...

PT-2026-86796

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: 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...

GHSA-6M44-FPC8-C3RQ Mistune: Denial of Service — RecursionError via Excessive Emphasis Markers in Markdown

Summary Mistune v3.3.2 is vulnerable to a Denial of Service DoS attack via uncontrolled recursion in the HTML rendering of deeply-nested emphasis tokens. By submitting Markdown containing approximately 1,000 consecutive asterisk characters, an attacker causes the Python process to crash with...

Mistune: Denial of Service — RecursionError via Excessive Emphasis Markers in Markdown

Summary Mistune v3.3.2 is vulnerable to a Denial of Service DoS attack via uncontrolled recursion in the HTML rendering of deeply-nested emphasis tokens. By submitting Markdown containing approximately 1,000 consecutive asterisk characters, an attacker causes the Python process to crash with...

GHSA-J8PM-GJ4C-RQ4X league/commonmark: Denial of service via crafted code fences, reference links, and emphasis delimiters

Impact Affected versions of league/commonmark perform super-linear work on three independent parsing paths, all of which are reachable on a stock new CommonMarkConverter with default configuration and no extensions registered. Each trigger fits on a single line of input, so no complex Markdown...

CVE-2026-76098

A flaw was found in Mistune, a Python Markdown parser. This vulnerability allows a remote attacker to trigger a Denial of Service DoS by submitting specially crafted Markdown input. The excessive use of emphasis markers, such as consecutive asterisks, creates deeply nested tokens during HTML...

Uncontrolled Recursion

Overview Affected versions of this package are vulnerable to Uncontrolled Recursion through the InlineParser emphasis processing in src/mistune/inlineparser.py. An attacker can crash the Python process by supplying Markdown with a very long run of emphasis markers, such as hundreds or thousands o...

DEBIAN-CVE-2026-76098

Mistune is a Python Markdown parser with renderers and plugins. Versions 3.3.0 through 3.3.2 are vulnerable to DoS through deeply nested tokens. HTML rendering creates deeply nested emphasis tokens from consecutive asterisk characters, and recursive rendering in HTMLRenderer.rendertoken can excee...

CVE-2026-76098

Mistune is a Python Markdown parser with renderers and plugins. Versions 3.3.0 through 3.3.2 are vulnerable to DoS through deeply nested tokens. HTML rendering creates deeply nested emphasis tokens from consecutive asterisk characters, and recursive rendering in HTMLRenderer.rendertoken can excee...

UBUNTU-CVE-2026-76098

Mistune is a Python Markdown parser with renderers and plugins. Versions 3.3.0 through 3.3.2 are vulnerable to DoS through deeply nested tokens. HTML rendering creates deeply nested emphasis tokens from consecutive asterisk characters, and recursive rendering in HTMLRenderer.rendertoken can excee...

CVE-2026-76098 Mistune has Denial of Service — RecursionError via Excessive Emphasis Markers in Markdown

Mistune is a Python Markdown parser with renderers and plugins. Versions 3.3.0 through 3.3.2 are vulnerable to DoS through deeply nested tokens. HTML rendering creates deeply nested emphasis tokens from consecutive asterisk characters, and recursive rendering in HTMLRenderer.rendertoken can excee...

CVE-2026-76098 Mistune has Denial of Service — RecursionError via Excessive Emphasis Markers in Markdown

Mistune is a Python Markdown parser with renderers and plugins. Versions 3.3.0 through 3.3.2 are vulnerable to DoS through deeply nested tokens. HTML rendering creates deeply nested emphasis tokens from consecutive asterisk characters, and recursive rendering in HTMLRenderer.rendertoken can excee...

CVE-2026-76098 Mistune has Denial of Service — RecursionError via Excessive Emphasis Markers in Markdown

Mistune is a Python Markdown parser with renderers and plugins. Versions 3.3.0 through 3.3.2 are vulnerable to DoS through deeply nested tokens. HTML rendering creates deeply nested emphasis tokens from consecutive asterisk characters, and recursive rendering in HTMLRenderer.rendertoken can excee...

CVE-2026-64209

In the Linux kernel, the following vulnerability has been resolved: phy: qcom: qmp-usbc: Fix out-of-bounds array access in dp swing config swingtbl and preemphasistbl are 4x4 arrays valid indices 0-3, but the boundary check uses " 4" instead of "= 4", allowing index 4 to cause an out-of-bounds...