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

What is CVE-2026-25891?

CVE-2026-25891 is a high-severity path traversal vulnerability in gofiber fiber, published on 24 Feb 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official 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.

Weakness: CWE-22

Which versions are affected by CVE-2026-25891?

3 open source packages ship an affected version, including github.com/gofiber/fiber/v3. It affects 1 product.

Products include Gofiber Fiber.

How do I fix CVE-2026-25891?

Upgrade github.com/gofiber/fiber/v3 to 3.1.0 or later.

Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.

Is CVE-2026-25891 being exploited?

There is no known exploitation of CVE-2026-25891 in the wild and no public exploit code.

Other vulnerabilities in gofiber fiber

• CVE-2024-38513 Fiber Session Middleware Token Injection Vulnerability Critical 10.0
• CVE-2023-45128 CSRF Token Reuse Vulnerability in fiber Critical 10.0
• CVE-2024-25124 Fiber has Insecure CORS Configuration, Allowing Wildcard Origin with Credentials Critical 9.4
• CVE-2025-66630 Fiber insecurely fallsback in utils.UUIDv4() / utils.UUID() — predictable / zero‑UUID on crypto/rand failure Critical 9.2
• CVE-2025-54801 Fiber Susceptible to Crash via `BodyParser` Due to Unvalidated Large Slice Index in Decoder High 8.7

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-m3c2-496v-cw3v, GO-2026-4540.