Bug 2491908 (CVE-2026-52846) - CVE-2026-52846 github.com/caddyserver/caddy: Caddy: Client-side Cross-Site Scripting (XSS) due to incomplete HTML tag stripping
Summary: CVE-2026-52846 github.com/caddyserver/caddy: Caddy: Client-side Cross-Site Sc...
Keywords:
Status: NEW
Alias: CVE-2026-52846
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security
QA Contact:
URL:
Whiteboard:
Depends On: 2499696 2499697
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-06-23 19:02 UTC by OSIDB Bzimport
Modified: 2026-07-18 08:28 UTC (History)
26 users (show)

Fixed In Version:
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Description OSIDB Bzimport 2026-06-23 19:02:50 UTC 
Caddy is an extensible server platform that uses TLS by default. Prior to 2.11.4, Caddy’s stripHTML template function cannot reliably remove all HTML tags from input strings. Certain malformed HTML, such as <<>img src=x onerror=alert()>, can bypass the tag-stripping logic, potentially leaving dangerous content in the output if it is later rendered as HTML. This may allow client-side XSS in cases where untrusted strings are rendered unsafely. This vulnerability is fixed in 2.11.4.
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