Description
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.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| github | cmark-gfm | < 0.29.0.gfm.10 | — |
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 | 1.9.1-1 | — |
| 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 | 1.9.1-1 | — |
| 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 26.10 | cmark | No fix yet | — |
| Ubuntu 26.04 LTS | cmark | No fix yet | — |
| Ubuntu 25.10 | cmark | No fix yet | — |
| Ubuntu 24.04 LTS | cmark | No fix yet | — |
| Ubuntu 22.04 LTS | cmark | No fix yet | — |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | cmark | No fix yet | — |
| Ubuntu 18.04 LTS | cmark | No fix yet | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 8 | pandoc +1 | 2.0.6-7.el8_10 | RHSA-2025:8427 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 8 | pandoc +1 | 2.0.6-7.el8_10 | ALSA-2025:8427 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 8 | pandoc | 2.0.6-7.el8_10 | RLSA-2025:8427 |
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| Hackage | cmark-gfm | >= 0.1.0, < 0.2.6 | 0.2.6 | HSEC-2025-0007 |
Advisories 4
- ALSA-2025:8427 Moderate: pandoc security update AlmaLinux Security Advisories · Oct 29, 2026
- RHSA-2025:8427 Red Hat Security Advisory: pandoc security update Red Hat Security Advisories (RHSA) · Jun 29, 2026
- RLSA-2025:8427 Moderate: pandoc security update Rocky Linux Security Advisories · Jul 29, 2025
- WID-SEC-2025-1213 Red Hat Enterprise Linux (cmark-gfm): Schwachstelle ermöglicht Denial of Service BSI CERT-Bund (WID) · Jun 2, 2025