🛡️ CVE-2023-37463 — cmark-gfm

🟡 CVSS 6.4 — Medium ⚠️ Exploit Public CWE-400 NVD

6.4

CVSS Score

0 Low4 Medium7 High9 Critical10

Description

cmark-gfm is an extended version of the C reference implementation of CommonMark, a rationalized version of Markdown syntax with a spec. Three polynomial time complexity issues in cmark-gfm may lead to unbounded resource exhaustion and subsequent denial of service. These vulnerabilities have been patched in 0.29.0.gfm.12.

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is high, an attacker needs low-level privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality low, integrity low, availability high.

Weakness class

CVE-2023-37463 is classified as CWE-400: Uncontrolled Resource Consumption. A request can consume memory, CPU or storage without limit, exhausting capacity for everyone else.

Affected software

CVE-2023-37463 is recorded against 1 package.

cmark-gfm (fixed in 0.29.0.gfm.12)

Timeline and source

Published on 13 July 2023 and last revised on 17 June 2026. A public exploit is known to exist, which raises the urgency of patching considerably. Record sourced from NVD.

References

github.com
github.com
github.com
github.com

CVE-2023-37463 on other distributions

Each distribution ships its own build and its own fixed version. Pick the one you run:

Debian Ubuntu

Details

Severity MEDIUM

CVSS Score 6.4

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

CWE CWE-400

Public Exploit ⚠️ Yes

Source NVD

Published 2023-07-13

Updated 2026-08-20

Modified 2026-06-17

Fix URL N/A

Affected Packages

Software	From version	Fixed in
cmark-gfm	—	0.29.0.gfm.12

References

Release Notes https://github.com/github/cmark-gfm/releases/tag/0.29.0.gfm.12

Exploit https://github.com/github/cmark-gfm/security/advisories/GHSA-w4qg-3vf7-m9x5

Release Notes https://github.com/github/cmark-gfm/releases/tag/0.29.0.gfm.12

Exploit https://github.com/github/cmark-gfm/security/advisories/GHSA-w4qg-3vf7-m9x5

🔗 NVD 🔗 Mitre

Similar Threats

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