CVE-2026-2191: Tenda AC9 formGetDdosDefenceList stack-based overflow

Vulnerability summary

CVE-2026-2191 is a high (CVSS 8.6) vulnerability in tenda ac9_firmware. EPSS estimates a 0.77% chance of exploitation in the next 30 days, higher than 55.1% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 08-02-2026
   PublishedVulnerability first disclosed.
2. 23-02-2026
   Last modifiedVulnerability information updated.

Description

A weakness has been identified in Tenda AC9 15.03.06.42_multi. Affected is the function formGetDdosDefenceList. This manipulation of the argument security.ddos.map causes stack-based buffer overflow. The attack may 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).