Machine-written summary
Summary written by Claude Haiku from the source advisory. Not reviewed by a person.
gRPC-Go versions before 1.79.3 are vulnerable to an authorization bypass: the server accepts HTTP/2 requests whose :path lacks the leading slash, and authorization interceptors then evaluate that non-canonical path, so deny rules may not match. An attacker who can send crafted HTTP/2 requests directly to the server can bypass policy when a fallback allow rule exists. Upgrade to gRPC-Go 1.79.3 or later. Alternatively, a validating interceptor placed outermost can reject paths without a leading slash, and a default-deny authorization policy reduces exposure.
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 |
|---|---|---|---|---|
| 9.1 | Critical | 3.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N | CNA (GitHub_M) |
- CISA KEV Not listed.
- EPSS 0.016, the 75th percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.
Timeline
- 31 Oct 2026, 14:14 UTC First seen by agentprime
- 31 Oct 2026, 14:14 UTC Confirmed by OSV