Machine-written summary
Summary written by Claude Haiku from the source advisory. Not reviewed by a person.
Gitea versions before 1.27.0 are vulnerable to a denial-of-service attack through the Accept-Language header processed by the Locale middleware on unauthenticated requests. A remote attacker sending one crafted request with a large header of underscore-separated malformed tags can make the server use about 2 seconds of CPU per request, and multiple concurrent requests can exhaust the CPU. Upgrade to Gitea 1.27.0 or later. The source gives no other workaround.
Not analysed yet
We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.
Severity and exploitation
| Score | Rating | CVSS | Vector | Source |
|---|---|---|---|---|
| 7.5 | High | 3.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | ADP (CISA-ADP) |
- CISA KEV Not listed.
- EPSS 0.0061, the 49th percentile, on 15 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.
Timeline
- 31 Oct 2026, 14:58 UTC First seen by agentprime
- 31 Oct 2026, 14:58 UTC Confirmed by OSV