Vulnerability · Published Feb 24, 2026 · Assigned by GitHub_M

CVE-2026-25882Fiber has a Denial of Service Vulnerability via Route Parameter Overflow

Medium 5.5

In plain English

A medium-severity security flaw in fiber from gofiber. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.7% (higher than 52% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 4.0)5.5Medium

Exploit odds (30 days)0.7%top 48.0% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

Fiber is an Express inspired web framework written in Go. A denial of service vulnerability exists in Fiber v2 and v3 that allows remote attackers to crash the application by sending requests to routes with more than 30 parameters. The vulnerability results from missing validation during route registration combined with an unbounded array write during request matching. Version 2.52.12 patches the issue in the v2 branch and 3.1.0 patches the issue in the v3 branch.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Go	github.com/gofiber/fiber/v2	2.52.12	GO-2026-4543
Go	github.com/gofiber/fiber/v2	2.52.12	GHSA-mrq8-rjmw-wpq3
Go	github.com/gofiber/fiber/v3	3.1.0	GO-2026-4543
Go	github.com/gofiber/fiber/v3	3.1.0	GHSA-mrq8-rjmw-wpq3

Affected products (as reported)

Vendor	Product	Versions
gofiber	fiber	>= 2.0.0, < 2.52.12>= 3.0.0, < 3.1.0

Weakness: CWE-129 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P

References

https://github.com/gofiber/fiber/security/advisories/GHSA-mrq8-rjmw-wpq3 x_refsource_CONFIRM
https://github.com/gofiber/fiber/pull/3962 x_refsource_MISC
https://github.com/gofiber/fiber/blob/main/path.go#L514 x_refsource_MISC
https://github.com/gofiber/fiber/blob/v2/path.go#L516 x_refsource_MISC