# CVE-2026-121600: TOTOLINK A950RG MAC Filter cstecgi.cgi setMacFilterRules stack-based overflow

- Exploited (CISA KEV): no
- Published: 2026-11-04
- CVSS: 9.4 CRITICAL (v4.0)
- EPSS: no score
- CWE: CWE-121, CWE-119

A flaw has been found in TOTOLINK A950RG 4.1.2cu.5268_B20221104. Affected by this vulnerability is the function setMacFilterRules of the file /cgi-bin/cstecgi.cgi of the component MAC Filter Handler. This manipulation of the argument addEffect causes stack-based buffer overflow. The attack can be initiated remotely. The exploit has been published and may be used.

## Edge WAF coverage (claimed by vendors, not measured)

| Vendor | Status | First rule | Days after publication |
|---|---|---|---|
| Cloudflare | No public claim | — | — |
| AWS | No public claim | — | — |
| Microsoft Azure | No public claim | — | — |
| Google Cloud | No public claim | — | — |
| Fastly | No public claim | — | — |
| Vercel | No public claim | — | — |
| F5 | No public claim | — | — |
| Akamai | No public source | — | — |
| OWASP CRS | No public claim | — | — |

## Social

1 posts seen since 2026-11-04.

- bluesky 2026-11-04: CVE-2026-121600 CRITICAL (CVSS 9.9) A flaw has been found in TOTOLINK A950RG 4.1.2cu.5268_B20221104 Fix: https://patchthecve.com/cve/CVE-2026-121600.html (https://bsky.app/profile/patchthecve.bsky.social/post/3mzh6fccna52w)

"No public claim" means no vendor statement names this CVE; "Before feed history" means the CVE is older than the vendor feed. In both cases generic rules may still block it.

HTML: https://cve.vigilbase.com/cve/CVE-2026-121600 · JSON: https://cve.vigilbase.com/api/v1/cves/CVE-2026-121600