Tenda CP3 3.0/31.1.9.91 RTSP Parser Content-Length memory leak

Summaryinfo

A vulnerability was found in Tenda CP3 3.0/31.1.9.91. It has been declared as critical. This affects an unknown part of the component RTSP Parser. Executing a manipulation of the argument Content-Length can lead to memory leak. This vulnerability is handled as CVE-2026-51600. The attack can be executed remotely. There is not any exploit available.

Detailsinfo

A vulnerability classified as critical was found in Tenda CP3 3.0/31.1.9.91. This vulnerability affects some unknown processing of the component RTSP Parser. The manipulation of the argument Content-Length with an unknown input leads to a memory leak vulnerability. The CWE definition for the vulnerability is CWE-401. The product does not sufficiently track and release allocated memory after it has been used, which slowly consumes remaining memory. As an impact it is known to affect availability. CVE summarizes:

Tenda CP3 V3.0 firmware V31.1.9.91 does not validate the Content-Length header field in RTSP requests (including DESCRIBE, SETUP, and PLAY methods). When a request carrying a Content-Length header is received without a corresponding message body, the RTSP parser enters a persistent body-awaiting state, causing the affected TCP connection to become permanently non-functional. The device does not actively close the connection, resulting in a TCP resource leak. This issue can be exploited by an unauthenticated remote attacker to cause a denial-of-service condition.

The advisory is shared for download at github.com. This vulnerability was named CVE-2026-51600 since 06/08/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. There are known technical details, but no exploit is available. The MITRE ATT&CK project declares the attack technique as T1499.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

• Router Operating System

Vendor

• Tenda

Name

• CP3

Version

• 3.0
• 31.1.9.91

License

• commercial

Website

• Vendor: https://www.tenda.com.cn/

CPE 2.3info

• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

Once again VulDB remains the best source for vulnerability data.

Discussion