Buffer overflow in Totolink Ca300-Poe
CVE-2026-123957
A vulnerability was determined in TOTOLINK CA300-PoE 6.2c.884. Impacted is the function setIpQosRules of the file /cgi-bin/cstecgi.cgi. This manipulation of the argument ipStart causes buffer overflow. It is possible to initiate the attack remotely. The exploit has been publicly disclosed and may be utilized.
Vulnerability class: Buffer Overflow
Published · last modified .
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 Ca300-Poe — versions 6.2c.884
Weakness classification (CWE)
References
- lavender-bicycle-a5a.notion.site/TOTOLINK-CA300-PoE-setIpQosRules-3f953a41781f8… (exploit)
- vuldb.com/cve/CVE-2026-123957 (third-party-advisory)
- vuldb.com/submit/1033672 (third-party-advisory)
- vuldb.com/vuln/432020 (technical-description, vdb-entry)
- vuldb.com/vuln/432020/cti (signature, permissions-required)
- www.totolink.net/ (product)
Frequently asked questions
- What is CVE-2026-123957?
- CVE-2026-123957 is a critical-severity vulnerability in Totolink Ca300-Poe, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 9.9/10. Published 2026-11-07.
- How severe is CVE-2026-123957?
- Critical severity. CVSS v3 base score is 9.9 out of 10.