CVE-2026-35201 Discount has an Out-of-bounds Read in rdiscount
An out-of-bounds read in the Discount Markdown parser allows attackers to crash the application by supplying inputs larger than INT_MAX.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-35201?
CVE-2026-35201 is a medium-severity memory corruption vulnerability in davidfstr rdiscount, published on 6 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Discount is an implementation of John Gruber's Markdown markup language in C. From 1.3.1.1 to before 2.2.7.4, a signed length truncation bug causes an out-of-bounds read in the default Markdown parse path. Inputs larger than INT_MAX are truncated to a signed int before entering the native parser, allowing the parser to read past the end of the supplied buffer and crash the process. This vulnerability is fixed in 2.2.7.4.
Weakness: CWE-125
Which versions are affected by CVE-2026-35201?
2 open source packages ship an affected version, including rdiscount. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
rdiscount RubyGems | From 1.3.1.1 | 2.2.7.4 |
rdiscount RubyGems | From 1.3.1.1 | 2.2.7.4 |
Products include Dafoster Rdiscount.
How do I fix CVE-2026-35201?
Upgrade rdiscount to 2.2.7.4 or later.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-35201 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-35201 exists.
Sources
Also known as AZL-82902, DEBIAN-CVE-2026-35201, GHSA-6r34-94wq-jhrc, UBUNTU-CVE-2026-35201.