CVE-2026-56755 Denial of Service (CPU & Memory Exhaustion) via O(N^2) String Concatenation in Debian Package Upload
An attacker can cause CPU and memory exhaustion in Gitea by exploiting inefficient string concatenation during package uploads.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-56755?
CVE-2026-56755 is a medium-severity denial of service vulnerability in Gitea Open Source Git Server, published on 13 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
Denial of Service (CPU & Memory Exhaustion) via O(N^2) String Concatenation in Debian Package Upload
Weakness: CWE-284
Which versions are affected by CVE-2026-56755?
3 open source packages ship an affected version, including code.gitea.io/gitea and gitea.dev.
| Package | Affected | Fixed in |
|---|---|---|
code.gitea.io/gitea Go | All versions | 1.27.0 |
code.gitea.io/gitea Go | All versions | 1.27.0 |
gitea.dev Go | All versions | 1.27.0 |
How do I fix CVE-2026-56755?
Upgrade code.gitea.io/gitea to 1.27.0 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-2026-56755 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-56755 exists.
Sources
Also known as GHSA-6hm7-3pwj-22rm, GO-2026-6037, MINI-gj5r-8q7r-x8mj, MINI-qw9v-86r2-x98j.