Buffer overflow in Totolink Ca300-Poe
CVE-2026-123958
A vulnerability was identified in TOTOLINK CA300-PoE 6.2c.884. The affected element is the function setLanConfig of the file /cgi-bin/cstecgi.cgi. Such manipulation of the argument lanDns/lanSecDns/langType leads to buffer overflow. It is possible to launch the attack remotely. The exploit is publicly available and might be used.
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-setLanConfig-3f953a41781f80… (exploit)
- CVE-2026-123958 | CVE Analysis and Report (third-party-advisory)
- Submit #1033673 | TOTOLINK CA300-PoE CA300-PoE_Firmware V6.2c.884 Buffer Overflow (third-party-advisory)
- VDB-432021 | TOTOLINK CA300-PoE cstecgi.cgi setLanConfig buffer overflow (technical-description, vdb-entry)
- VDB-432021 | CTI Indicators (IOB, IOC, IOA) (signature, permissions-required)
- www.totolink.net/ (product)
Frequently asked questions
- What is CVE-2026-123958?
- CVE-2026-123958 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-2026-123958?
- Critical severity. CVSS v3 base score is 9.9 out of 10.