CVE-2026-52846: Caddy is an extensible server platform that uses TLS by default

Q: How do I fix CVE-2026-52846?

caddy: upgrade to 2.11.4. Exact commands for each OS are on this page.

Q: Is CVE-2026-52846 being exploited?

CVE-2026-52846 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-52846 affect?

CVE-2026-52846 affects caddy. Severity is medium (CVSS 4.2). 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()>, ca

Routine

MEDIUM 4.2UPGRADE

CVE-2026-52846 is a medium-severity flaw (CVSS 4.2) affecting caddy. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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

Why this priority

Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	4.2 (Medium)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.2% (top 84%)
CISA exploited list	No
Weakness	CWE-116
Published	2026-06-23
Last modified	2026-06-29

Publisher (CNA): GitHub, Inc. · Vendor: caddyserver

Last updated 2026-06-29 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-06-23 18:18 UTCPublished CVE record published
2026-06-29 19:08 UTCUpdated Record last modified

caddyserver caddy UPGRADE

Affected: < 2.11.4

Fixed in: 2.11.4

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy caddy || rpm -q caddy || caddy --version

2. UPGRADE to 2.11.4 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade caddy

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade caddy

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-52846?

caddy: upgrade to 2.11.4. Exact commands for each OS are on this page.

Is CVE-2026-52846 being exploited?

CVE-2026-52846 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-52846 affect?

CVE-2026-52846 affects caddy. Severity is medium (CVSS 4.2). 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()>, ca

How urgent is CVE-2026-52846?

Priority 24/100. Public exploit reference

Software pages

Caddy vulnerabilities

Related CVEs

CVE-2026-45135 HIGH 8.1 UPGRADE Caddy is an extensible server platform that uses TLS by default
CVE-2026-52844 HIGH 7.5 UPGRADE Caddy is an extensible server platform that uses TLS by default
CVE-2026-52845 HIGH 8.1 UPGRADE Caddy is an extensible server platform that uses TLS by default
CVE-2026-45692 MEDIUM 5.4 UPGRADE Caddy is an extensible server platform that uses TLS by default

References

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