What is CVE-2026-121600?

CVE-2026-121600 is a critical-severity vulnerability in Totolink A950rg, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 9.9/10. Published 2026-11-04.

How severe is CVE-2026-121600?

Critical severity. CVSS v3 base score is 9.9 out of 10.

Buffer overflow in Totolink A950rg

CVE-2026-121600

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.

Vulnerability class: Buffer Overflow

Published 2026-11-04 · last modified 2026-11-04.

CVSS v3 metric

CVSS v3 base score 9.9 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Totolink A950rg — versions 4.1.2cu.5268_B20221104

Weakness classification (CWE)

References

vuldb.com/vuln/430442 (technical-description, vdb-entry)
vuldb.com/vuln/430442/cti (signature, permissions-required)
vuldb.com/cve/CVE-2026-121600 (third-party-advisory)
vuldb.com/submit/1022562 (third-party-advisory)
gist.github.com/H3rmesk1t/217c00b12e04fcde07c453a55579f808 (exploit)
www.totolink.net/ (product)

Frequently asked questions

What is CVE-2026-121600?: CVE-2026-121600 is a critical-severity vulnerability in Totolink A950rg, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 9.9/10. Published 2026-11-04.
How severe is CVE-2026-121600?: Critical severity. CVSS v3 base score is 9.9 out of 10.