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Fencer Vulns
low 3.5

CVE-2023-22486 json

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

published 2023-01-24 3 y ago modified 2026-06-17 4 mo ago also EUVD-2023-26633

cvss
3.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.1%
EPSS 1.1% chance of exploitation in 30 days, percentile 66%
public exploits
0
none known

Summary

cmark-gfm is GitHub's fork of cmark, a CommonMark parsing and rendering library and program in C. Versions prior to 0.29.0.gfm.7 contain a polynomial time complexity issue in handle_close_bracket that may lead to unbounded resource exhaustion and subsequent denial of service. This vulnerability has been patched in 0.29.0.gfm.7.

Patch / fix

  • github cmark-gfm 0.29.0.gfm.7
  • 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 1.9.0-1
  • ruby-commonmarker Debian 14, Debian 13 0.23.10-1

debian advisories DEBIAN-CVE-2023-22486

  • cmark-gfm Ubuntu Pro 20.04 LTS 0.29.0.gfm.0-4ubuntu0.1~esm1
  • cmark-gfm Ubuntu Pro 22.04 LTS 0.29.0.gfm.3-3ubuntu0.1~esm1
  • cmark-gfm Ubuntu Pro 24.04 LTS 0.29.0.gfm.6-6ubuntu0.24.04.1~esm1

ubuntu advisories UBUNTU-CVE-2023-22486

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • cmark SLE Module for Package Hub 15 SP4, SLE Module for Development Tools 15 SP4, openSUSE Leap 15.4 0.30.2-150400.3.3.1

suse advisories SUSE-SU-2023:1834-1

  • cmark openSUSE Tumbleweed 0.30.3-1.1

opensuse advisories openSUSE-SU-2024:12802-1

  • cmark Alpine 3.24, Alpine 3.23, Alpine 3.22 +5 more 0.30.3-r0

alpine advisories ALPINE-CVE-2023-22486

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

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-2023-22486 updated

cmark-gfm: multiple vulnerabilities

  • Red Hat All currently supported Red Hat products
    not affected: vulnerable code not present

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
no
Technical impact
partial
Assessed
19 mo ago

Exploit prediction

1.12% chance of exploitation in the next 30 days, higher than 66% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/github/cmark-gfm/security/advisories/GHSA-r572-jvj2-3m8p referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 3.5 CVSS:3.1/AV:A/AC:L/PR:L/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

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.