Fiber is a web framework for Go. Prior to 2.52.12 and 3.1.0, Cross-Site Scripting vulnerability in Go Fiber allows a remote attacker to inject arbitrary HTML/JavaScript by supplying Accept: text/html on any request whose handler passes attacker-influenced data to the AutoFormat() feature. The developer opts into content negotiation by calling AutoFormat(), but does not opt into raw HTML emission for a particular request; Fiber chooses that branch from attacker-controlled Accept. The html branch is the sole outlier in a method whose name (AutoFormat) and symmetrical structure actively telegraph "safe, format-agnostic reply." This vulnerability is fixed in 2.52.12 and 3.1.0.
Fix
Patch, vendor advisory and mitigation references on NVD 2
- https://github.com/gofiber/fiber/security/advisories/GHSA-qjv7-627w-8qjv Exploit, Mitigation, Vendor Advisory
- https://github.com/gofiber/fiber/security/advisories/GHSA-qjv7-627w-8qjv Exploit, Mitigation, Vendor Advisory
Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.
Change history 1
- First seenCVSS 5.3 · gofiberNVD modified 2026-10-26 18:10
Affected (CPE criteria) 1
cpe:2.3:a:gofiber:fiber:*:*:*:*:*:go:*:*
References 2
- https://github.com/gofiber/fiber/security/advisories/GHSA-qjv7-627w-8qjv Exploit, Mitigation, Vendor Advisory
- https://github.com/gofiber/fiber/security/advisories/GHSA-qjv7-627w-8qjv Exploit, Mitigation, Vendor Advisory