How severe is CVE-2026-39915?

CVE-2026-39915 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability none.

Is CVE-2026-39915 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (39th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-39915?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2026-39915 published?

CVE-2026-39915 was published on 2026-08-24 and last updated on 2026-09-24.

CVE-2026-39915

CVE-2026-39915 is a high-severity vulnerability with a CVSS 3.x base score of 8.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-113.

Key facts

Severity: High (CVSS 3.x base score 8.1)
CVSS v4: 8.5
EPSS exploit prediction: 0% (39th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-113
Published: 2026-08-24
Last modified: 2026-09-24

Description

TIM Flow before 26.0.6 contains a CRLF injection vulnerability that allows remote attackers to inject arbitrary HTTP headers and response body content by embedding unsanitized carriage return and line feed sequences in the rt URL parameter, which is reflected into Set-Cookie response headers. 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.

Frequently asked questions

What is CVE-2026-39915?: TIM Flow before 26.0.6 contains a CRLF injection vulnerability that allows remote attackers to inject arbitrary HTTP headers and response body content by embedding unsanitized carriage return and line feed sequences in the rt URL parameter, which is reflected into Set-Cookie response headers. 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.
How severe is CVE-2026-39915?: CVE-2026-39915 has a CVSS 3.x base score of 8.1, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability none.
Is CVE-2026-39915 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (39th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-39915?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2026-39915 published?: CVE-2026-39915 was published on 2026-08-24 and last updated on 2026-09-24.

References

Other CWE-113 (HTTP Response Splitting) vulnerabilities

CVE-2026-67289 — Critical (CVSS 9.8): FreeRDP before 3.29.0 (affected versions <= 3.28.0) does not validate CRLF and control characters in the…
CVE-2026-38967 — Critical (CVSS 9.8): CrowCpp Crow through v1.3.1 HTTP is vulnerable to response header injection via unvalidated response header values.
CVE-2026-105324 — Critical (CVSS 9.2): An HTTP header injection vulnerability in start-page-loader.cgi of ADM allows an unauthenticated remote attacker to…
CVE-2026-34520 — Critical (CVSS 9.1): AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.13.4, the C parser…
CVE-2025-53007 — High (CVSS 8.9): arduino-esp32 provides an Arduino core for the ESP32. Versions prior to 3.3.0-RC1 and 3.2.1 contain a HTTP Response…
CVE-2026-75419 — High (CVSS 8.8): go-wind-cms (GoWind) before 1.0.0 has a missing authorization vulnerability. The NewAuthorizer() function in…

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