CVE-2026-115349

Mistune from 3.0.0 before 3.3.0 contains an algorithmic complexity denial of service vulnerability in the parse_link_text function in src/mistune/helpers.py. Attackers can submit markdown with deeply nested square brackets triggering quadratic parsing time, exhausting server CPU with small crafted requests.

CVSS v3 7.5 HIGH

7.5^/10

CVSS v3 : HIGH

Vector :

Exploitability : 3.9 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://github.com/lepture/mistune/security/advisories/GHSA-3q64-rw38-243v
https://www.vulncheck.com/advisories/mistune-3.0.0-before-3.3.0-denial-of-service-via-nested-bracket-parsing

Configurations

No configuration.

History

22 Oct 2026, 19:17

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-10-22 19:17

Updated : 2026-10-26 20:17

NVD link : CVE-2026-115349

Mitre link : CVE-2026-115349

CVE.ORG link : CVE-2026-115349

JSON object : View

Products Affected

No product.

CWE

CWE-1333

Inefficient Regular Expression Complexity

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