CVE-2026-4961: Tenda AC6 POST Request QuickIndex formQuickIndex stack-based overflow

Vulnerability summary

CVE-2026-4961 is a high (CVSS 9.0) vulnerability in tenda ac6_firmware. EPSS estimates a 1.01% chance of exploitation in the next 30 days, higher than 62.7% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 27-03-2026
   PublishedVulnerability first disclosed.
2. 27-03-2026
   Last modifiedVulnerability information updated.

Description

A vulnerability was identified in Tenda AC6 15.03.05.16. Affected by this vulnerability is the function formQuickIndex of the file /goform/QuickIndex of the component POST Request Handler. The manipulation of the argument PPPOEPassword leads to stack-based buffer overflow. The attack is possible to be carried out remotely. The exploit is publicly available and might be used.

• 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.