What’s Vulnerable › Vulnerabilities

CVE-2026-55677: Echo: Encoded slash (%2F) bypasses route-level protection and exposes static files

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-06-26 · updated 2026-10-25
• Weakness: CWE-22

Description

Echo is a Go web framework. Prior to 4.15.3 and 5.2.0, Echo's router and static file handler disagree on URL path decoding. The router matches routes using the raw encoded path (preserving %2F as-is), while StaticDirectoryHandler unescapes %2F to / before resolving filesystem paths. This allows an attacker to bypass route-level access controls and read static files without authorization. This vulnerability is fixed in 4.15.3 and 5.2.0.

Affected products

• labstack echo: before 4.15.3; from 5.0.0, < 5.2.0

References

• https://github.com/labstack/echo/security/advisories/GHSA-vfp3-v2gw-7wfq
• https://github.com/labstack/echo/security/advisories/GHSA-vfp3-v2gw-7wfq

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