EUVD-2026-42336

Mistune renderers/html.safeurl: HARMFULPROTOCOLS list misses legacy and chained schemes that historically chain to javascript: execution...

MGASA-2026-0254 Updated python-mistune package fixes security vulnerabilities

The updated python-mistune package fixes two security vulnerablities: Prior to 3.2.1, rendertocul builds a table-of-contents tree from a list of level, id, text tuples. Both the id value used as href="" and the text value used as the visible link label are inserted into tags via a plain Python...

UBUNTU-CVE-2026-59929

Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.3.0, the safeurl filter in src/mistune/renderers/html.py blocks only javascript:, vbscript:, file:, and data: schemes, allowing legacy or chained schemes such as feed:, view-source:, jar:, livescript:, mocha:, ms-its:, mk:...

UBUNTU-CVE-2026-59928

Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.3.0, a Markdown document containing many repeated or distinct reference-link definitions causes quadratic work in src/mistune/blockparser.py and the reflinks environment dictionary handling, allowing denial of service...

UBUNTU-CVE-2026-59924

Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.3.0, Include.parse joins and normalizes user-supplied include paths without verifying that the result remains within the intended markdown directory, allowing crafted include paths to access files outside that directory wh...

UBUNTU-CVE-2026-59925

Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.3.0, long sequences of well-formed double-asterisk or triple-asterisk emphasis pairs around a character cause quadratic work in src/mistune/inlineparser.py because the parser scans forward for matching close markers from...

UBUNTU-CVE-2026-59926

Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.2.1, renderadmonition in src/mistune/directives/admonition.py concatenates the Admonition directive :class: option into the HTML class attribute without escaping, allowing attribute injection and cross-site scripting even...

UBUNTU-CVE-2026-44897

Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.2.1, HTMLRenderer.heading builds the opening tag by string-concatenating the id attribute value directly into the HTML — with no call to escape, safeentity, or any other sanitisation function. A double-quote character " in...

EUVD-2026-27877

Mistune has a ReDoS in LINKTITLERE that allows denial of service via crafted Markdown input...

CVE-2026-44897

creationtimestamp| type| source ---|---|--- 2026-05-06 07:13:48+00:00| published-proof-of-concept| https://github.com/lepture/mistune/security/advisories/GHSA-v87v-83h2-53w7...

GHSA-FW3V-X4F2-V673 Mistune vulnerable to catastrophic backtracking

In Mistune through 2.0.2, support of inline markup is implemented by using regular expressions that can involve a high amount of backtracking on certain edge cases. This behavior is commonly named catastrophic backtracking...

PYSEC-2017-18

Cross-site scripting XSS vulnerability in the keyify function in mistune.py in Mistune before 0.8.1 allows remote attackers to inject arbitrary web script or HTML by leveraging failure to escape the "key" argument...

UBUNTU-CVE-2017-16876

Cross-site scripting XSS vulnerability in the keyify function in mistune.py in Mistune before 0.8.1 allows remote attackers to inject arbitrary web script or HTML by leveraging failure to escape the "key" argument...