Header Injection Affecting github.com/caddyserver/caddy/v2/modules/caddyhttp/reverseproxy/forwardauth package, versions >=2.10.0 <2.11.2
Threat Intelligence
Snyk has a proof-of-concept or detailed explanation of how to exploit this vulnerability.
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-GOLANG-GITHUBCOMCADDYSERVERCADDYV2MODULESCADDYHTTPREVERSEPROXYFORWARDAUTH-15440580
- published10 Mar 2026
- disclosed6 Mar 2026
- creditnewklei
Introduced: 6 Mar 2026
CVE-2026-30851 (opens in a new tab)How to fix?
Upgrade github.com/caddyserver/caddy/v2/modules/caddyhttp/reverseproxy/forwardauth to version 2.11.2 or higher.
Overview
Affected versions of this package are vulnerable to Header Injection in the parseCaddyfile function. An attacker can inject arbitrary values into trusted identity headers by supplying crafted HTTP headers when authenticated with a valid token, leading to unauthorized privilege escalation in backend services.