CVE-2023-24824 Quadratic complexity may lead to a denial of service in cmark-gfm
Attackers can cause denial of service in cmark-gfm by submitting crafted input with excessive characters, leading to resource exhaustion.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2023-24824?
CVE-2023-24824 is a medium-severity denial of service vulnerability in github cmark-gfm, published on 31 Mar 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Which versions are affected by CVE-2023-24824?
1 open source package ship an affected version, including cmark-gfm. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
cmark-gfm Hackage | From 0.1.0 | 0.2.6 |
Linux distribution packages (5)
pandoc AlmaLinux:8 | All versions | 2.0.6-7.el8_10 |
pandoc-common AlmaLinux:8 | All versions | 2.0.6-7.el8_10 |
pandoc Red Hat:enterprise_linux:8::crb | All versions | 0:2.0.6-7.el8_10 |
pandoc-common Red Hat:enterprise_linux:8::crb | All versions | 0:2.0.6-7.el8_10 |
pandoc Rocky Linux:8 | All versions | 0:2.0.6-7.el8_10 |
Products include Github Cmark-Gfm.
How do I fix CVE-2023-24824?
Upgrade cmark-gfm to 0.2.6 or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2023-24824 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2023-24824 exists.
Other vulnerabilities in github cmark-gfm
- CVE-2024-22051 CommonMarker Integer Overflow Vulnerability
- CVE-2023-37463 Quadratic complexity bugs may lead to a denial of service
- CVE-2023-26485 Quadratic complexity may lead to a denial of service in cmark-gfm
- CVE-2023-22485 cmark-gfm out-of-bounds read in validate_protocol
- CVE-2023-22486 cmark-gfm Quadratic complexity bug in handle_close_bracket may lead to a denial of service
Sources
Also known as ALSA-2025:8427, DEBIAN-CVE-2023-24824, GHSA-66g8-4hjf-77xh, HSEC-2025-0007, RHSA-2025:8427, RLSA-2025:8427 and 1 more.