CVE-2026-52846

Caddy: stripHTML template function bypass

MEDIUM
4.2
CVSS Score
Published: June 23, 2026 at 05:47 PM UTC
Updated: July 1, 2026 at 11:22 PM UTC
1 product affected across 1 vendorCaddy

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Severity
MEDIUM4.2
Exploit prediction
EPSS 0.2%
SSVC
PoC

Description

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 2.11.4
Affected range stops below 2.11.4, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

References (1)

x_refsource_CONFIRMExploitThird Party Advisory
Source: cverecord
https://github.com/caddyserver/caddy/security/advisories/GHSA-vcc4-2c75-vc9v

SSVC — Action Prioritization

SSVCPoCNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

4.2MEDIUMGitHub_M
Attack Vector
NETWORK
Complexity
HIGH
Privileges
NONE
User Interaction
REQUIRED
Scope
UNCHANGED
Confidentiality
LOW
Integrity
LOW
Availability
NONE
Vector?

Quick Info

StatusANALYZED
CWE
CWE-116

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