CVE-2026-25891: Fiber has an Arbitrary File Read in Static Middleware on Windows

Vulnerability summary

CVE-2026-25891 is a high (CVSS 7.7) Path Traversal vulnerability in gofiber fiber. EPSS estimates a 0.77% chance of exploitation in the next 30 days, higher than 55.2% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 24-02-2026
   PublishedVulnerability first disclosed.
2. 24-02-2026
   Last modifiedVulnerability information updated.

Description

Fiber is an Express inspired web framework written in Go. A Path Traversal (CWE-22) vulnerability in Fiber allows a remote attacker to bypass the static middleware sanitizer and read arbitrary files on the server file system on Windows. This affects Fiber v3 through version 3.0.0. This has been patched in Fiber v3 version 3.1.0.

• CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.