Echo: Encoded slash (%2F) bypasses route-level protection and exposes static files

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

• CISA KEV Not listed.
• EPSS 0.0052, the 44th percentile, on 12 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

1. 14 Jun 2026, 15:08 UTC Published by the maintainers as a GitHub repository advisory
2. 31 Oct 2026, 14:13 UTC First seen by agentprime
3. 31 Oct 2026, 14:13 UTC Confirmed by OSV

Sources

• GitHub Advisory Database: GHSA-vfp3-v2gw-7wfq
• OSV: GHSA-vfp3-v2gw-7wfq
• github.com/labstack/echo/security/advisories/GHSA-vfp3-v2gw-7wfq
• nvd.nist.gov/vuln/detail/CVE-2026-55677
• github.com/labstack/echo/pull/3009
• github.com/labstack/echo/pull/3011
• github.com/labstack/echo/commit/8d1ae9d3360a71672418856d58753af25f2c3986
• github.com/labstack/echo/commit/c3fa2a27ff92b2b8db360de614f999ef1da24725
• github.com/labstack/echo
• github.com/labstack/echo/releases/tag/v4.15.3
• github.com/labstack/echo/releases/tag/v5.2.0

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.