Vulnerability · Published Jul 9, 2026 · Assigned by GitHub_M

CVE-2026-50188Kirby: Request header injection in `Http\Remote`

Medium 6.9

In plain English

A medium-severity security flaw in kirby from getkirby. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 39% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 4.0)6.9Medium

Exploit odds (30 days)0.4%top 61.3% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

Kirby is an open-source content management system. Prior to 4.9.4 and 5.4.4, Kirby sites and plugins using the Kirby Http Remote class, including Remote::request(), Remote::get(), and Remote::post(), to send outgoing HTTP requests with untrusted data in the headers option could allow newline characters in a header value to inject a separate unintended request header to the remote service. This issue is fixed in versions 4.9.4 and 5.4.4.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Packagist	getkirby/cms	4.9.4	GHSA-4v4h-m2qq-ppgw
Packagist	getkirby/cms	5.4.4	GHSA-4v4h-m2qq-ppgw

Affected products (as reported)

Vendor	Product	Versions
getkirby	kirby	< 4.9.4>= 5.0.0, < 5.4.4

Weakness: CWE-93, CWE-113 · Vector: CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:H/SA:N

References

https://github.com/getkirby/kirby/security/advisories/GHSA-4v4h-m2qq-ppgw x_refsource_CONFIRM
https://github.com/getkirby/kirby/commit/aa33414e1669e866cdd6f4decfae2a669e8bb828 x_refsource_MISC
https://github.com/getkirby/kirby/commit/fad9cbd22c73ed0fbd3aaf62310a8dcacfc007cd x_refsource_MISC
https://github.com/getkirby/kirby/releases/tag/4.9.4 x_refsource_MISC
https://github.com/getkirby/kirby/releases/tag/5.4.4 x_refsource_MISC