CVE-2026-49276 getkirby CVE debrief

Who should care

Administrators and users of the Kirby CMS, particularly those using the writer field in any blueprint, should be aware of this vulnerability and take immediate action to update to a patched version. Affected operators and security teams should review the vulnerability and implement necessary mitigations.

Technical summary

The vulnerability exists in the writer field of certain blueprints in Kirby CMS versions prior to 4.9.4 and 5.4.4. An attacker can inject a scripting link into the writer field, allowing for self cross-site scripting (XSS) in the Panel. This issue has been fixed in versions 4.9.4 and 5.4.4. Affected users should review and update any custom blueprints using the writer field, and administrators should ensure that all users are aware of the vulnerability and take necessary precautions to prevent exploitation. Additionally, users should monitor for suspicious activity in the Panel and review compensating controls for exposed systems while remediation is scheduled and verified.

Defensive priority

High

Recommended defensive actions

• Update to Kirby CMS version 4.9.4 or 5.4.4 or later
• Review and update any custom blueprints using the writer field
• Monitor for suspicious activity in the Panel
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented

Evidence notes

The CVE record was published on 2026-07-09T19:17:05.670Z and last modified on 2026-07-10T15:49:19.093Z. The NVD entry is currently Deferred. Evidence is limited to public sources and may not reflect the full scope or impact of this vulnerability. Defenders should verify affected systems and review vendor advisories for specific guidance.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.