---
title: "CVE-2026-115348: Mistune - Denial of Service"
description: "Mistune 3.0.0 < 3.3.0 contains an algorithmic complexity vulnerability caused by unbalanced brackets in the inline link parser's parse_link_text function, letting unauthenticated attackers exhaust CPU resources remotely."
url: https://panop.io/threat-heartbeat/CVE-2026-115348/
---

# CVE-2026-115348 Mistune - Denial of Service

Mistune 3.0.0 < 3.3.0 contains an algorithmic complexity vulnerability caused by unbalanced brackets in the inline link parser's parse\_link\_text function, letting unauthenticated attackers exhaust CPU resources remotely.

CVSS base score 7.5 /10

High

CISA KEV

Not listed

Public exploit

None known

Authentication

Not required

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-115348)

## Details

Type

Denial of Service

Impact

Denial Of Service

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Published

22 October 2026

Updated

23 October 2026

Weakness

[CWE-400](https://cwe.mitre.org/data/definitions/400.html)

## Vendor fix

Upgrade to version 3.3.0 or later.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-115348](https://nvd.nist.gov/vuln/detail/CVE-2026-115348)
- [https://github.com/lepture/mistune/security/advisories/GHSA-x2gr-6qf2-fc9x](https://github.com/lepture/mistune/security/advisories/GHSA-x2gr-6qf2-fc9x)
- [https://www.vulncheck.com/advisories/mistune-before-3.3.0-quadratic-time-dos-via-parse-link-text](https://www.vulncheck.com/advisories/mistune-before-3.3.0-quadratic-time-dos-via-parse-link-text)

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## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

Panop answers these inside your environment, for this CVE and every other finding.

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