Vulnerability · Published May 5, 2026 · Assigned by GitHub_M

CVE-2026-30246github.com/gofiber/fiber/v3 cache middleware can mix responses across query parameters

Medium 6.5

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 0.3% (higher than 17% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)6.5Medium
Exploit odds (30 days)0.3%top 83.4% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known

Official description

Fiber is a web framework for Go. In github.com/gofiber/fiber/v3 versions through 3.1.0, the default key generator in the cache middleware uses only the request path and does not include the query string. As a result, requests for the same path with different query parameters can share a cache key and receive the wrong cached response. This can cause response mix-up for query-dependent endpoints and may expose data intended for a different request. This issue is fixed after version 3.1.0.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Gogithub.com/gofiber/fiber/v33.2.0GHSA-35hp-hqmv-8qg8
Gogithub.com/gofiber/fiber/v33.2.0GO-2026-5069

Affected products (as reported)

VendorProductVersions
gofiber fiber >= v3.0.0-beta.2, < 3.1.0

Weakness: CWE-436 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

References