High severity · published Jun 26, 2026
CVE-2026-55677
Echo: Encoded slash (%2F) bypasses route-level protection and exposes static files
7.5
CVSS
0.5%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
None
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.5% · higher than 44% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
EC
echo · labstack
< 4.15.3; >= 5.0.0, < 5.2.0 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-55677
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-55677
github.com
https://github.com/labstack/echo/security/advisories/GHSA-vfp3-v2gw-7wfq
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