# CVE-2026-121598: TOTOLINK A950RG Basic Wireless Configuration cstecgi.cgi strcpy 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 security vulnerability has been detected in TOTOLINK A950RG 4.1.2cu.5268_B20221104. This impacts the function strcpy of the file /cgi-bin/cstecgi.cgi of the component Basic Wireless Configuration Handler. The manipulation of the argument wepkey leads to stack-based buffer overflow. It is possible to initiate the attack remotely. The exploit has been disclosed publicly 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

3 posts seen since 2026-11-04.

- x 2026-11-04: CVE-2026-121598: TOTOLINK A950RG firmware 4.1.2cu.5268_B20221104 has a remote stack overflow. https://t.co/klZ4GJwQ03: CVSS 3.1 9.9 Critical; low privileges required; public exploit cited.  Not in CISA KEV. Active exploitation unconfirmed; no fix listed. https://t.co/QTrEx9uz1B… (https://x.com/busenur038/status/2117872247822299456)
- x 2026-11-04: 🆕 New CVEs TOTOLINK A950RG: 3 critical CVEs Worst: code execution via stack overflow in wireless config (CVE-2026-121598) No patch listed yet https://t.co/sBjut2pkab (https://x.com/cvedotnow/status/2117867857375556067)
- bluesky 2026-11-04: CVE-2026-121598 CRITICAL (CVSS 9.9) A security vulnerability has been detected in TOTOLINK A950RG 4.1.2cu.5268_B20221104 Fix: https://patchthecve.com/cve/CVE-2026-121598.html (https://bsky.app/profile/patchthecve.bsky.social/post/3mzh6fffusc2f)

"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-2026-121598 · JSON: https://cve.vigilbase.com/api/v1/cves/CVE-2026-121598