How severe is CVE-2026-52846?

CVE-2026-52846 has a CVSS 3.x base score of 4.2, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2026-52846 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (5th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-52846?

CVE-2026-52846 affects Caddyserver Caddy. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-52846?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-52846 have an EU (EUVD) identifier?

Yes. CVE-2026-52846 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-38556.

When was CVE-2026-52846 published?

CVE-2026-52846 was published on 2026-06-23 and last updated on 2026-06-29.

CVE-2026-52846

CVE-2026-52846 is a medium-severity vulnerability in Caddyserver Caddy with a CVSS 3.x base score of 4.2. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-116.

Key facts

Severity: Medium (CVSS 3.x base score 4.2)
EPSS exploit prediction: 0% (5th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-38556
Weakness: CWE-116
Affected product: Caddyserver Caddy
Published: 2026-06-23
Last modified: 2026-06-29

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.

Frequently asked questions

What is CVE-2026-52846?: 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.
How severe is CVE-2026-52846?: CVE-2026-52846 has a CVSS 3.x base score of 4.2, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2026-52846 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (5th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-52846?: CVE-2026-52846 affects Caddyserver Caddy. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-52846?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-52846 have an EU (EUVD) identifier?: Yes. CVE-2026-52846 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-38556.
When was CVE-2026-52846 published?: CVE-2026-52846 was published on 2026-06-23 and last updated on 2026-06-29.

References

https://github.com/caddyserver/caddy/security/advisories/GHSA-vcc4-2c75-vc9v

Affected products (1)

cpe:2.3:a:caddyserver:caddy:*:*:*:*:*:*:*:*

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