Home / mailings [SECURITY] [DSA 6429-1] caddy security update
Posted on 11 August 2026
Debian Security Advisory- -------------------------------------------------------------------------
Debian Security Advisory DSA-6429-1 security@debian.org
https://www.debian.org/security/ Aron Xu
August 11, 2026 https://www.debian.org/security/faq
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Package : caddy
CVE ID : CVE-2026-27585 CVE-2026-27587 CVE-2026-27588 CVE-2026-27589
CVE-2026-27590 CVE-2026-45692 CVE-2026-52845 CVE-2026-52846
Multiple security issues were discovered in Caddy, a web server with
automatic HTTPS, which may result in the bypass of path- or host-based
access controls, the execution of an unintended file by a FastCGI
backend, the injection of identity headers trusted by applications
running behind Caddy, unauthorised reconfiguration of the server through
its admin API, or cross-site scripting.
The fix for CVE-2026-52845 follows upstream in dropping every request
header whose name contains an underscore, for all servers and without an
opt-out. Deployments which pass such headers through Caddy, for instance
X_Api_Key or gRPC custom metadata keys containing underscores, need to
switch to the hyphenated spelling.
For the stable distribution (trixie), these problems have been fixed in
version 2.6.2-12+deb13u1.
We recommend that you upgrade your caddy packages.
For the detailed security status of caddy please refer to
its security tracker page at:
https://security-tracker.debian.org/tracker/caddy
Further information about Debian Security Advisories, how to apply
these updates to your system and frequently asked questions can be
found at: https://www.debian.org/security/
Mailing list: debian-security-announce@lists.debian.org
