CVE-2026-13189 Progress Software CVE debrief

Who should care

Users of Progress Telerik UI for AJAX prior to v2026.2.708 should verify their systems and apply patches or mitigations as recommended by the vendor. Operators, platform administrators, vulnerability management teams, and security teams should review the official advisory and CVE record to validate affected scope, severity, and vendor guidance.

Technical summary

In Progress Telerik UI for AJAX prior to v2026.2.708, insufficient validation of the language parameter in the spell check handler may allow an attacker to influence server-side file path resolution and trigger unintended server-side requests. This issue has a CVSS score of 7.5 and is classified as HIGH severity. Affected product deployments should be identified and patched or mitigated as soon as possible.

Defensive priority

High priority should be given to patching or mitigating this vulnerability, as it could potentially lead to unauthorized server-side requests. Defenders should review compensating controls for exposed systems while remediation is scheduled and verified. Monitoring, detection, and logs for exposed assets should be checked for extra review. Additional security measures, such as input validation and sanitization, should be implemented to prevent similar vulnerabilities in the future. Systems should be reviewed for unusual or unauthorized server-side requests. Asset inventory and rollback/change windows should be considered for exposed systems. Source tracking and exposure review should be performed to ensure comprehensive vulnerability management.

Recommended defensive actions

• Verify and apply the latest patches or updates for Progress Telerik UI for AJAX
• Review and adjust server-side configurations to limit the impact of insufficient validation
• Monitor systems for unusual or unauthorized server-side requests
• Implement additional security measures, such as input validation and sanitization

Evidence notes

The CVE record and NVD entry provide limited information about the vulnerability. Further investigation and verification are necessary to fully understand the impact and scope of this issue. The official CVE record and NVD entry should be reviewed for additional details. Defenders should verify affected product deployments and review compensating controls.

Official resources