PatchSiren

PatchSiren cyber security CVE debrief

CVE-2026-39400 jhuckaby CVE debrief

CVE-2026-39400 is a medium severity vulnerability in Cronicle, a multi-server task scheduler and runner. A non-admin user with create_events and run_events privileges can inject arbitrary JavaScript through job output fields. The server stores this data without sanitization, and the client renders it via innerHTML on the Job Details page. This issue was fixed in version 0.9.111. The vulnerability allows for stored cross-site scripting (XSS) attacks, which can lead to unauthorized actions or data breaches. Users of Cronicle versions prior to 0.9.111 should apply the patch to prevent JavaScript injection attacks.

Vendor
jhuckaby
Product
Cronicle
CVSS
MEDIUM 5.3
CISA KEV
Not listed in stored evidence
Original CVE published
2026-04-07
Original CVE updated
2026-07-24
Advisory published
2026-04-07
Advisory updated
2026-07-24

Who should care

Users of Cronicle versions prior to 0.9.111 should apply the patch to prevent JavaScript injection attacks. This fix is particularly important for environments where non-admin users have create_events and run_events privileges. System administrators and security teams responsible for Cronicle deployments should prioritize patching to mitigate the risk of stored XSS attacks.

Technical summary

CVE-2026-39400 is a stored cross-site scripting (XSS) vulnerability in Cronicle. A non-admin user with create_events and run_events privileges can inject arbitrary JavaScript through job output fields (html.content, html.title, table.header, table.rows, table.caption). The server stores this data without proper sanitization, and the client renders it via innerHTML on the Job Details page. This vulnerability was fixed in Cronicle version 0.9.111. The vulnerability can be exploited by injecting malicious JavaScript code, potentially leading to unauthorized access or modifications.

Defensive priority

Apply the patch to prevent JavaScript injection attacks. Review and limit create_events and run_events privileges for non-admin users. Monitor for suspicious activity on the Job Details page and review compensating controls for exposed systems.

Recommended defensive actions

  • Apply the patch to Cronicle, updating to version 0.9.111 or later.
  • Review and limit create_events and run_events privileges for non-admin users.
  • Monitor for suspicious activity on the Job Details page.
  • 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.
  • Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up.

Evidence notes

The CVE record was published on 2026-04-07T21:17:18.333Z and last modified on 2026-07-24T21:10:00.143Z. The NVD entry is currently Analyzed. This information is based on the NVD entry and the CVE record. The vulnerability affects Cronicle versions prior to 0.9.111. Users should verify their deployments and apply patches accordingly.

Official resources

AI-assisted PatchSiren debrief based on the supplied source corpus. The CVE record was published on 2026-04-07T21:17:18.333Z and has not been modified since then. The NVD entry is currently Analyzed.