Description
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 are subject to several polynomial time complexity issues in cmark-gfm that may lead to unbounded resource exhaustion and subsequent denial of service. Various commands, when piped to cmark-gfm with large values, cause the running time to increase quadratically. These vulnerabilities have been patched in version 0.29.0.gfm.7.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| github | cmark-gfm | < 0.29.0.gfm.7 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | cmark-gfm | 0.29.0.gfm.13-1 | — |
| Debian 14 | python-cmarkgfm | 2024.11.20-1 | — |
| Debian 14 | r-cran-commonmark | 1.9.0-1 | — |
| Debian 14 | ruby-commonmarker | 0.23.10-1 | — |
| Debian 13 | cmark-gfm | 0.29.0.gfm.13-1 | — |
| Debian 13 | python-cmarkgfm | 2024.11.20-1 | — |
| Debian 13 | r-cran-commonmark | 1.9.0-1 | — |
| Debian 13 | ruby-commonmarker | 0.23.10-1 | — |
| Debian 12 | cmark-gfm +3 | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 24.04 LTS | cmark-gfm | 0.29.0.gfm.6-6ubuntu0.24.04.1~esm1 | USN-7319-1 |
| Ubuntu Pro 22.04 LTS | cmark-gfm | 0.29.0.gfm.3-3ubuntu0.1~esm1 | USN-7319-1 |
| Ubuntu Pro 20.04 LTS | cmark-gfm | 0.29.0.gfm.0-4ubuntu0.1~esm1 | USN-7319-1 |
Advisories 1
- USN-7319-1 cmark-gfm vulnerabilities Ubuntu Security Notices (USN) · Apr 27, 2026