CVE catalog
CVE-2026-42554
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
- Severity
- Medium · CVSS 5.4
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N - Published
- Source
- [NVD] · [CVE record]
- EPSS
- 0.21% · Oct 25, 2026
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.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Cpe | fiber | Not reported | 2.52.12 | fixed |
| Cpe | fiber | Not reported | 3.1.0 | fixed |
| Cpe | fiber | Not reported | 3.1.0 | fixed |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Cpe | fiber | cpe | Not reported | 2.52.12 | Not reported | Not reported | Not reported |
| Cpe | fiber | cpe | Not reported | 3.1.0 | Not reported | Not reported | Not reported |
| Cpe | fiber | cpe | Not reported | 3.1.0 | Not reported | NVD-CVE-2026-42554 | Not reported |
OpenFactory catalog packages
No matching packages in this catalog.
Observed: