---
title: "CVE-2026-118694: python-markdown2 - Denial of Service"
description: "python-markdown2 <= 2.5.5 contains a denial of service caused by unclosed inline link destinations in Markdown, letting remote attackers exhaust CPU by submitting repeated link sequences, exploit requires crafted Markdown input."
url: https://panop.io/threat-heartbeat/CVE-2026-118694/
---

# CVE-2026-118694 python-markdown2 - Denial of Service

python-markdown2 <= 2.5.5 contains a denial of service caused by unclosed inline link destinations in Markdown, letting remote attackers exhaust CPU by submitting repeated link sequences, exploit requires crafted Markdown input.

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-2026-118694)

## 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

28 October 2026

Updated

29 October 2026

Weakness

[CWE-407](https://cwe.mitre.org/data/definitions/407.html)

## Vendor fix

Update to the latest version of python-markdown2.

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-2026-118694](https://nvd.nist.gov/vuln/detail/CVE-2026-118694)
- [https://github.com/trentm/python-markdown2/blob/2.5.5/lib/markdown2.py#L3029](https://github.com/trentm/python-markdown2/blob/2.5.5/lib/markdown2.py#L3029)
- [https://github.com/trentm/python-markdown2/issues/750](https://github.com/trentm/python-markdown2/issues/750)
- [https://github.com/trentm/python-markdown2/pull/751](https://github.com/trentm/python-markdown2/pull/751)
- [https://www.vulncheck.com/advisories/python-markdown2-through-2.5.5-denial-of-service-via-unclosed-inline-link-destinations](https://www.vulncheck.com/advisories/python-markdown2-through-2.5.5-denial-of-service-via-unclosed-inline-link-destinations)
- [https://github.com/trentm/python-markdown2](https://github.com/trentm/python-markdown2)
- [https://github.com/trentm/python-markdown2/blob/2.5.5/lib/markdown2.py#L1478-L1492](https://github.com/trentm/python-markdown2/blob/2.5.5/lib/markdown2.py#L1478-L1492)

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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

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