CVE-2026-49276: Kirby: Self cross-site scripting (self-XSS) in the writer field

high Affects getkirby/cms. Feed 2026.10.29.4, updated 2026-10-29; published 2026-06-18; advisory modified 2026-09-10.

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

Package: getkirby/cms Composer
Affected versions: <4.9.4 or >=5.0.0-alpha.1 and <5.4.4
Fixed in: 4.9.4, 5.4.4
Severity: high
Exploitation: not on CISA KEV · EPSS 0% (37.5th percentile)
Published: 2026-06-18
Source: osv.dev

References

Am I affected?

Find out in one command. phpwarden checks your composer.lock against this advisory and 20,000+ others, ranked by real-world exploitation (CISA KEV + EPSS). Free, offline, open data.

# PHP projects (recommended)
composer require --dev phpwarden/phpwarden
# then
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pipx install phpwarden   &&   phpwarden deps composer.lock

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