CVE-2026-39915 TIM Solutions CVE debrief

Who should care

Defenders responsible for TIM Flow deployments should assess exposure and potential impact, as authenticated users may be vulnerable to session token theft and account credential modification.

Why it matters

CVE-2026-39915 is a high-severity vulnerability in TIM Flow that allows remote attackers to inject arbitrary HTTP headers and response body content, potentially leading to session token theft and account credential modification. Defenders should prioritize verifying exposure and assessing potential impact.

• Session token theft and account credential modification are possible consequences of this vulnerability
• Defenders must verify exposure and assess potential impact on authenticated users
• Compensating controls and monitoring are necessary to detect and prevent malicious requests

Technical summary

The vulnerability exists in TIM Flow before version 26.0.6, where the rt URL parameter is not properly sanitized, allowing attackers to inject arbitrary HTTP headers and response body content. This can lead to session token theft and account credential modification. Attackers can craft malicious requests to induce authenticated users to execute arbitrary JavaScript in their browser context, enabling session token theft and account credential modification. Defenders should prioritize verifying exposure and assessing potential impact, as the vulnerability allows for arbitrary JavaScript execution in the browser context of authenticated users.

Defensive priority

Defenders should prioritize verifying exposure and assessing potential impact, as the vulnerability allows for arbitrary JavaScript execution in the browser context of authenticated users.

Recommended defensive actions

• Verify exposure by checking the version of TIM Flow in use
• Assess potential impact on authenticated users
• Implement compensating controls to detect and prevent malicious requests
• Monitor for suspicious activity and update to version 26.0.6 or later
• Review 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 and NVD entry provide details on the vulnerability, but the scope of affected versions and potential impact require further verification. The rt URL parameter in TIM Flow before version 26.0.6 is not properly sanitized, allowing attackers to inject arbitrary HTTP headers and response body content. Defenders should verify exposure by checking the version of TIM Flow in use and assess potential impact on authenticated users. Compensating controls and monitoring are necessary to detect and prevent malicious requests.

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.