Description
commonmark versions from 1.5.0 before 2.8.4 contain a denial of service vulnerability in the Footnote extension that fails to deduplicate footnote definitions. Attackers can craft documents with duplicate footnote definitions and references to create quadratic output expansion, consuming excessive memory and CPU to exhaust server resources.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| thephpleague | commonmark | 1.5.0 – < 2.8.4 | 2.8.4 |
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 | php-league-commonmark | 2.9.0-1 | — |
| Debian 13 | php-league-commonmark | No fix yet | — |
| Debian 12 | php-league-commonmark | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.04 LTS | php-league-commonmark | No fix yet | — |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 24.04 LTS | php-league-commonmark | No fix yet | — |
| Ubuntu Pro 22.04 LTS | php-league-commonmark | No fix yet | — |
| Ubuntu Pro 20.04 LTS | php-league-commonmark | No fix yet | — |
References
- GitHub Security Advisory (GHSA-jfm3-95jq-q3rf) vendor-advisory
- VulnCheck Advisory: commonmark 1.5.0 before 2.8.4 Denial of Service via Footnote third-party-advisory