CVE-2022-39209

Uncontrolled Resource Consumption in cmark-gfm

MEDIUM
6.5
CVSS Score
Published: September 15, 2022 at 12:00 AM UTC
Updated: June 17, 2026 at 04:57 AM UTC
2 products affected across 2 vendorsFedoraCmark Gfm

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Severity
MEDIUM6.5
Exploit prediction
EPSS 2%
SSVC
No known exploit

Description

cmark-gfm is GitHub's fork of cmark, a CommonMark parsing and rendering library and program in C. In versions prior to 0.29.0.gfm.6 a polynomial time complexity issue in cmark-gfm's autolink extension may lead to unbounded resource exhaustion and subsequent denial of service. Users may verify the patch by running `python3 -c 'print("![l"* 100000 + "\n")' | ./cmark-gfm -e autolink`, which will resource exhaust on unpatched cmark-gfm but render correctly on patched cmark-gfm. This vulnerability has been patched in 0.29.0.gfm.6. Users are advised to upgrade. Users unable to upgrade should disable the use of the autolink extension.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Cmark Gfm· GitHubgithub-action
95%
v < 0.29.0.gfm.6
Affected range stops below 0.29.0.gfm.6, so it looks safe — our inference, not a vendor statement

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-400CWE-407

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