Markdown Parsing Vulnerability in Mistune Python Library
CVE-2026-44708

6.1MEDIUM

Key Information:

Vendor

Lepture

Status
Mistune
Vendor
CVE Published:
26 May 2026

What is CVE-2026-44708?

The Mistune Markdown parser, a widely-used Python library for rendering Markdown, is susceptible to a vulnerability that permits unsafe rendering of user-supplied content in HTML. Specifically, prior to version 3.2.1, the math plugin of Mistune allowed inline and block math to be rendered without adequate HTML escaping. This oversight raised security concerns by exposing applications to cross-site scripting (XSS) attacks, as user-controlled mathematical expressions could be injected directly into the HTML output. To mitigate this issue, it is essential to update to Mistune version 3.2.1 or higher, where this vulnerability has been addressed.

Affected Version(s)

mistune < 3.2.1

References

https://github.com/lepture/mistune/security/advisories/GH...
x_refsource_CONFIRM
https://github.com/lepture/mistune/releases/tag/v3.2.1
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CVSS V3.1

Score:
6.1
Severity:
MEDIUM
Confidentiality:
Low
Integrity:
Low
Availability:
Low
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
Required
Scope:
Changed

Timeline

  • Vulnerability published

  • Vulnerability Reserved

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