High severity · published Mar 7, 2026
CVE-2026-30851
Caddy forward_auth copy_headers Does Not Strip Client-Supplied Headers, Allowing Identity Injection and Privilege Escalation
8.8
CVSS
0.3%
EPSS
No
On KEV
Description
Caddy is an extensible server platform that uses TLS by default. From version 2.10.0 to before version 2.11.2, forward_auth copy_headers does not strip client-supplied headers, allowing identity injection and privilege escalation. This issue has been patched in version 2.11.2.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 18% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
CA
caddy · caddyserver
>= 2.10.0, < 2.11.2 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-30851
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-30851
Issue Tracking
https://github.com/caddyserver/caddy/issues/6610
Issue Tracking
https://github.com/caddyserver/caddy/pull/6608
Issue Tracking
https://github.com/caddyserver/caddy/pull/7545
Exploit
https://github.com/caddyserver/caddy/security/advisories/GHSA-7r4p-vjf4-gxv4
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