Quick answers
- Is CVE-2026-51603 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-51603 being exploited in the wild.
- How severe is CVE-2026-51603?
- Informational severity, with a CVSS score of 0, published 9 July 2026.
- Which products and versions are affected?
- Tenda CP3 V31.1.9.91.
- Is there a fix for CVE-2026-51603?
- No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
- How is CVE-2026-51603 attacked?
- It is attacked over the network, in a network appliance.
- Am I affected by CVE-2026-51603?
- Check whether you run Tenda CP3 at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
A stack-based buffer overflow exists in the RTSP service of Tenda CP3 V3.0 firmware V31.1.9.91. The vulnerability is located in the second-stage URL routing parser, which fails to validate the length of the URL field during a second SETUP request. To exploit this, an attacker must first complete the OPTIONS, DESCRIBE, and an initial legitimate SETUP handshake to obtain a valid session ID. By then sending a second SETUP request containing a URL composed of four consecutive repetitions of a valid RTSP URL, the attacker bypasses first-stage format validation and triggers the overflow. This results in an immediate crash of the RTSP process (typically on port 554), leading to a denial of service.
Affected products
- Tenda CP3 V3.0 V31.1.9.91
Timeline
- 2026-07-09: disclosed
- 2026-07-09: advisory