Description
The islist function in markdown.c in libmarkdown.a in DISCOUNT 2.2.3a allows remote attackers to cause a denial of service (heap-based buffer over-read) via a crafted file, as demonstrated by mkd2html.
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 | discount | 2.2.4-1 | — |
| Debian 13 | discount | 2.2.4-1 | — |
| Debian 12 | discount | 2.2.4-1 | — |
| Debian 9 | discount | 2.2.2-1+deb9u1 | DSA-4293-1 |
| Debian 8 | discount | 2.1.7-1+deb8u1 | DLA-1499-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 18.04 LTS | discount | No fix yet | — |
| Ubuntu 16.04 LTS | discount | No fix yet | — |
| Ubuntu 14.04 LTS | discount | 2.1.7-1+deb8u1build0.14.04.1 | — |
Advisories 2
- DSA-4293-1 discount - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-1499-1 discount - security update Debian Security (DSA / DLA) · Mar 9, 2026