CVE-2026-4254: Tenda AC8 HTTP Endpoint SysToolChangePwd doSystemCmd stack-based overflow

Vulnerability summary

CVE-2026-4254 is a high (CVSS 10.0) vulnerability in tenda ac8_firmware. EPSS estimates a 1.37% chance of exploitation in the next 30 days, higher than 71.6% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 16-03-2026
   PublishedVulnerability first disclosed.
2. 16-03-2026
   Last modifiedVulnerability information updated.

Description

A weakness has been identified in Tenda AC8 up to 16.03.50.11. This vulnerability affects the function doSystemCmd of the file /goform/SysToolChangePwd of the component HTTP Endpoint. This manipulation of the argument local_2c causes stack-based buffer overflow. The attack can be initiated remotely. The exploit has been made available to the public and could be used for attacks.

• CWE-119Improper Restriction of Operations within the Bounds of a Memory BufferThe product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.
• CWE-121Stack-based Buffer OverflowA stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function).
• CWE-787Out-of-bounds WriteThe product writes data past the end, or before the beginning, of the intended buffer.