TI-2026-33159 Aliases CVE-2026-45368 GHSA-qvjf-922g-pj44

Kirby: Cross-site scripting (XSS) from links in KirbyTags and image blocks in the site frontend

LOW 37CWE-79Published 2026-07-16 · Updated 2026-07-18

Key facts

Attack vector: Network
Privileges required: Low
User interaction: Active
Attack complexity: Low
Attack requirements: None
Impact type: Cross-site scripting
Confidentiality · integrity · availability: High · High · None
Fix status: Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub. Impact type from CWE-79.

Summary

Kirby is an open-source content management system. In versions prior to 4.9.1 and 5.4.1, the underlying URL methods for the KirbyTags and image blocks components did not filter out malicious URL values that resolve to script execution. The vulnerability affects four first-party Kirby renderers that produce `<a href="…">` output from editor-supplied field values: the (`link: …)` KirbyTag, the `link`: parameter of the `(image: …)` KirbyTag when it does not resolve to a known file or `self`, the `link` field of the built-in image block, and the HTML importer for the `blocks` field (which accepted the same malicious input as the image block `link` field). While simple `avascript:` URLs were already deactivated by treating them as a relative path and prepending a single slash to the URL, the use of URLs of the format `javascript://x%0A…` bypasses this protection. The `vbscript:`, `data:`, `livescript:`, `mocha:` and `jar:` schemes are affected by the same underlying gap. This issue has been fixed in versions 4.9.1 and 5.4.1.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00534 45th percentileScored 2026-11-07

Fix Fixed kirby (getkirby): 4.9.1, 5.4.1getkirby/cms (Packagist): 4.9.1, 5.4.1

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: No
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
getkirby	kirby	before 4.9.1; 5.0.0 to before 5.4.1	4.9.1, 5.4.1	Patch available	CNA
—	getkirby/cms (Packagist)	before 4.9.1	4.9.1	Patch available	GHSA-qvjf-922g-pj44
—	getkirby/cms (Packagist)	5.0.0 to before 5.4.1	5.4.1	Patch available	GHSA-qvjf-922g-pj44

kirby Vendorgetkirby Affected before 4.9.1; 5.0.0 to before 5.4.1 Fixed in 4.9.1, 5.4.1 Patch available CNA
getkirby/cms (Packagist) Vendor— Affected before 4.9.1 Fixed in 4.9.1 Patch available GHSA-qvjf-922g-pj44
getkirby/cms (Packagist) Vendor— Affected 5.0.0 to before 5.4.1 Fixed in 5.4.1 Patch available GHSA-qvjf-922g-pj44

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPE	Versions	Role	Vendor
cpe:2.3:a:getkirby:kirby::::::::	—	—	getkirby

cpe:2.3:a:getkirby:kirby:*:*:*:*:*:*:*:* Versions — — ·getkirby

Remediation

Fix · CNA kirby (getkirby) Fixed in 4.9.1, 5.4.1
Fix · GHSA-qvjf-922g-pj44 getkirby/cms (Packagist) Fixed in 4.9.1 Advisory →
Fix · GHSA-qvjf-922g-pj44 getkirby/cms (Packagist) Fixed in 5.4.1 Advisory →

Timeline

2026-10-02 Threatist record created from CVE-2026-45368
2026-10-03 Alias added: GHSA-qvjf-922g-pj44

References

Other 4

TI-2024-17440 An arbitrary file upload vulnerability in the Profile Image module of Kirby CMS v4.1.0… CVSS 3.1HIGH 8.8
TI-2024-17439 An HTML injection vulnerability exists in the Edit Content Layout module of Kirby CMS… CVSS 3.1HIGH 7.1
TI-2026-23396 Kirby CMS through 5.1.4 allows an authenticated user with 'Editor' permissions to cause a… CVSS 3.1MEDIUM 6.5
TI-2024-17441 A stored cross-site scripting (XSS) vulnerability in the Edit Content Layout module of… CVSS 3.1MEDIUM 6.1
TI-2018-10413 An issue was discovered in Kirby 2.5.12. CVSS 3.1MEDIUM 5.4
TI-2024-17438 Kirby CMS v4.1.0 was discovered to contain a reflected self-XSS vulnerability via the URL parameter. CVSS 3.1MEDIUM 4.7

See all 61 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences