CVE-2026-13186 Progress Software CVE debrief

Who should care

Organizations using Progress Telerik UI for AJAX prior to v2026.2.708 should be aware of this vulnerability and take necessary actions to mitigate the risk. This includes reviewing their deployments, assessing potential impact, and implementing necessary security measures to prevent exploitation.

Technical summary

The CVE-2026-13186 vulnerability is caused by a path traversal issue in the file-based persistence storage provider of Progress Telerik UI for AJAX. This vulnerability can be exploited when the storage key is derived from user-controlled input, enabling attacker-controlled deserialization and remote code execution. The CVSS score for this vulnerability is 8.1, indicating a high severity level. The vulnerability affects Progress Telerik UI for AJAX prior to v2026.2.708.

Defensive priority

High

Recommended defensive actions

• Update Progress Telerik UI for AJAX to v2026.2.708 or later
• Validate and sanitize user input to prevent path traversal
• Implement additional security measures to detect and prevent deserialization attacks
• 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-2026-13186 vulnerability was reported by an unknown vendor. The NVD entry is currently Undergoing Analysis. Limited information is available about the vulnerability, and further analysis is required to fully understand the impact. Defenders should verify the affected product deployments, review official advisories, and track exceptions. The storage key derivation from user-controlled input enables attacker-controlled deserialization and remote code execution.

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.