Cross-site Scripting (XSS) Affecting gatus package, versions <5.35.0-r11


Severity

Recommended
0.0
medium
0
10

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Threat Intelligence

EPSS
0.04% (13th percentile)

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  • Snyk IDSNYK-CHAINGUARDLATEST-GATUS-16437169
  • published7 May 2026
  • disclosed11 May 2026

Introduced: 7 May 2026

NewCVE-2026-42554  (opens in a new tab)
CWE-79  (opens in a new tab)

How to fix?

Upgrade Chainguard gatus to version 5.35.0-r11 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream gatus package and not the gatus package as distributed by Chainguard. See How to fix? for Chainguard relevant fixed versions and status.

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.

CVSS Base Scores

version 3.1