🛡️ CVE-2026-52845 on Debian — caddy
Description
Caddy is an extensible server platform that uses TLS by default. Prior to 2.11.4, forward_auth copy_headers deletes the exact client-supplied identity header before copying the trusted value from the auth gateway. But when the request later goes through php_fastcgi, Caddy normalizes HTTP headers into CGI variables by replacing - with _. This lets a client send an underscore alias that survives the forward_auth delete step but becomes the same PHP/FastCGI variable. Result: a remote client can inject or sometimes override identity/group headers trusted by PHP/FastCGI applications behind Caddy. This vulnerability is fixed in 2.11.4.
Distribution advisory
This page covers CVE-2026-52845 as tracked by Debian, for the package caddy. The fix is available in version 2.11.4-1; earlier versions remain affected.
How this vulnerability can be exploited
This issue can be reached over the network, attack complexity is low, an attacker needs low-level privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality high, integrity high, availability none.
Weakness class
DEBIAN-CVE-2026-52845 is classified as CWE-287: Improper Authentication. The identity of the caller is not established correctly, so an attacker can act as another user.
Affected software
DEBIAN-CVE-2026-52845 is recorded against 1 package.
- caddy (fixed in 2.11.4-1)
Timeline and source
Published on 23 June 2026 and last revised on 11 August 2026. No public exploit is currently recorded for this entry. Record sourced from OSV.
References
Details
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
Affected Packages
| Software | From version | Fixed in |
|---|---|---|
| caddy | — | 2.11.4-1 |
References
Similar Threats
- Unknown CGA-3x7g-jp4q-h9fr
- Unknown CGA-485h-x96h-hqh7
- Unknown CGA-2mv5-7p9w-vp27
- Unknown CGA-3w5r-2f79-3p9x
- Unknown CGA-33qc-7m28-fvwr
Site Security Check
Is caddy part of your stack?
DEBIAN-CVE-2026-52845 is rated CVSS 8.1 High. BotEraser scans your installation against known CVE records and tells you whether this vulnerability applies to the versions you actually run.
Scan My Site Free →No credit card required · Results in minutes
ⓘ Data Notice: The information presented above has been compiled from publicly available internet sources. Boteraser aggregates this data solely for informational purposes and does not independently classify, evaluate, or endorse any findings about the vulnerabilities listed. The accuracy and completeness of this information is the sole responsibility of the original publishers. Boteraser and its operators accept no liability for any decisions made based on this data.