CVE-2026-51603 — HIGH (7.5)

Vulnerability Description

A stack-based buffer overflow vulnerability in the RTSP service of Tenda CP3 V3.0 (firmware V31.1.9.91) allows an unauthenticated remote attacker to cause a denial of service via a crafted second SETUP request. After completing the OPTIONS, DESCRIBE, and a legitimate first SETUP request to obtain a valid session ID, the RTSP service's second-stage URL routing parser fails to validate the length of the URL field in the subsequent SETUP request. By supplying a URL consisting of exactly four consecutive repetitions of a valid RTSP URL, an attacker can bypass first-stage format validation and trigger a stack buffer overflow, causing an immediate crash of the RTSP service process and rendering the device inaccessible to all clients on the local network.

CVSS Score

7.5

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

NONE

Scope

UNCHANGED

Confidentiality

NONE

Integrity

NONE

Availability

HIGH

Related Weaknesses (CWE)

CWE-121

References

FAQ

What is CVE-2026-51603?

CVE-2026-51603 is a vulnerability with a CVSS score of 7.5 (HIGH). A stack-based buffer overflow vulnerability in the RTSP service of Tenda CP3 V3.0 (firmware V31.1.9.91) allows an unauthenticated remote attacker to cause a denial of service via a crafted second SETU...

How severe is CVE-2026-51603?

CVE-2026-51603 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-51603?

Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.