Skip to content
Fencer Vulns
medium 5.3

CVE-2023-24824 json

Quadratic complexity may lead to a denial of service in cmark-gfm

published 2023-03-31 3 y ago modified 2026-06-17 4 mo ago also EUVD-2023-28818 , GHSA-66g8-4hjf-77xh , HSEC-2025-0007

cvss
5.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.0%
EPSS 1.0% chance of exploitation in 30 days, percentile 64%
public exploits
0
none known

Summary

cmark-gfm is GitHub's fork of cmark, a CommonMark parsing and rendering library and program in C. A polynomial time complexity issue in cmark-gfm may lead to unbounded resource exhaustion and subsequent denial of service. This CVE covers quadratic complexity issues when parsing text which leads with either large numbers of `>` or `-` characters. This issue has been addressed in version 0.29.0.gfm.10. Users are advised to upgrade. Users unable to upgrade should validate that their input comes from trusted sources.

Patch / fix

  • hackage cmark-gfm 0.2.6
  • github cmark-gfm 0.29.0.gfm.10.
  • cmark-gfm Debian 14, Debian 13 0.29.0.gfm.13-1
  • python-cmarkgfm Debian 14, Debian 13 2024.11.20-1
  • r-cran-commonmark Debian 14, Debian 13 1.9.1-1
  • ruby-commonmarker Debian 14, Debian 13 0.23.10-1

debian advisories DEBIAN-CVE-2023-24824

  • pandoc RHEL 8 2.0.6-7.el8_10
  • pandoc-common RHEL 8 2.0.6-7.el8_10

red hat advisories RHSA-2025:8427

  • pandoc AlmaLinux 8 2.0.6-7.el8_10
  • pandoc-common AlmaLinux 8 2.0.6-7.el8_10

almalinux advisories ALSA-2025:8427

  • pandoc Rocky Linux 8 2.0.6-7.el8_10

rocky linux advisories RLSA-2025:8427

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2023-24824 updated cvss 7.5

cmark-gfm: Quadratic complexity bugs may lead to a denial of service

  • Red Hat 3scale API Management Platform 2 commonmarker commonmarker
    affected: workaround, no fix planned “No mitigation is currently available that meets Red Hat Product Security’s standards for usability, deployment, applicability, or stability.”
  • Red Hat Enterprise Linux CRB (v. 8) pandoc 2.0.6-7.el8_10, pandoc-common 2.0.6-7.el8_10
    fixed: vendor fix “No mitigation is currently available that meets Red Hat Product Security’s standards for usability, deployment, applicability, or stability.” RHSA-2025:8427

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
yes
Technical impact
partial
Assessed
20 mo ago

Exploit prediction

1.04% chance of exploitation in the next 30 days, higher than 64% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/github/cmark-gfm/security/advisories/GHSA-66g8-4hjf-77xh referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 5.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
OSV 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
hackage cmark-gfm
>=0.1.0, <0.2.6
0.2.6

Affected products

  • github cmark-gfm

Classification

Weakness
  • CWE-400 Uncontrolled Resource Consumption
  • CWE-407 Inefficient Algorithmic Complexity

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.