Machine-written summary
Summary written by Claude Haiku from the source advisory. Not reviewed by a person.
Starlette versions before 1.1.0 are affected. When an HTTPEndpoint subclass is registered through Route without an explicit methods argument, an attacker can send a non-standard HTTP method whose lowercased name matches a helper method on the endpoint, causing that helper to run as a request handler and bypassing checks applied to the intended handler. Upgrade to Starlette 1.1.0 or later. As a workaround, register HTTPEndpoint subclasses with an explicit methods list on the Route.
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 |
|---|---|---|---|---|
| 5.3 | Medium | 3.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N | CNA (GitHub_M) |
- CISA KEV Not listed.
- EPSS 0.0021, the 11th percentile, on 13 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.
Timeline
- 23 May 2026, 16:57 UTC Published by the maintainers as a GitHub repository advisory
- 31 Oct 2026, 14:35 UTC First seen by agentprime
- 31 Oct 2026, 14:35 UTC Confirmed by OSV