Kirby: Self cross-site scripting (self-XSS) in the writer field

published 2026-06-18 4 mo ago modified 2026-10-25 14 d ago also EUVD-2026-42671 , GHSA-rhj6-r49h-5932

cvss: 7.4; version 4.0, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.4%; EPSS 0.4% chance of exploitation in 30 days, percentile 37%
public exploits: 0; none known

Kirby is an open-source content management system. Prior to 4.9.4 and 5.4.4, Kirby sites using the writer field in any blueprint allowed a scripting link to be included as the target of a link or email link in writer mark components, making the target clickable by the user who entered it and enabling self cross-site scripting in the Panel. This issue is fixed in versions 4.9.4 and 5.4.4.

Patch / fix

fixed in 3 links 2

packagist getkirby/cms 4.9.4, 5.4.4
getkirby kirby 4.9.4, 5.4.4
getkirby panel 4.9.4, 5.4.4

github.com/getkirby/kirby/releases/tag/4.9.4 release
github.com/getkirby/kirby/releases/tag/5.4.4 release

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: total
Assessed: 4 mo ago (2026-07-10)

Exploit prediction

0.43% chance of exploitation in the next 30 days, higher than 37% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	4.0	7.4	CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:A/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
CNA	4.0	7.4	CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:A/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected packages

ecosystem	package	affected	fixed in
packagist	getkirby/cms	<4.9.4 >=5.0.0-alpha.1, <5.4.4	4.9.4 5.4.4

Affected products

getkirby kirby

Classification

Weakness

CWE-83 Improper Neutralization of Script in Attributes in a Web Page

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.

Summary