Machine-written summary
Summary written by Claude Haiku from the source advisory. Not reviewed by a person.
Echo v5 versions before 5.1.0 and Echo v4 versions 4.0.0 through 4.16.2 are affected. When IPExtractor is left unset, RealIP() trusts the client-supplied X-Forwarded-For header, so a remote attacker can rotate that header to get a fresh rate-limit bucket per request and bypass the default RateLimiter middleware. Upgrade echo v5 to 5.1.0 or later; no fixed version is listed for echo v4. Workaround: configure IPExtractor for your deployment, or set the rate limiter's IdentifierExtractor to a value clients cannot choose.
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 0.0042, the 36th percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.
Timeline
- 28 Oct 2026, 19:42 UTC Confirmed by the CVE List
- 28 Oct 2026, 20:17 UTC Confirmed by NVD
- 31 Oct 2026, 14:11 UTC First seen by agentprime
- 31 Oct 2026, 14:11 UTC Confirmed by OSV