Vulnerability · Published Nov 7, 2026 · Assigned by VulDB
CVE-2026-123958TOTOLINK CA300-PoE cstecgi.cgi setLanConfig buffer overflow
Critical 9.9
In plain English
A critical-severity buffer overflow in CA300-PoE from TOTOLINK. There are no confirmed reports of exploitation so far.
Severity (CVSS 3.1)9.9Critical
Exploit odds (30 days)–no EPSS score yet
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known
Official description
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.
Affected products (as reported)
Weakness: CWE-120, CWE-119 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H/E:P/RL:X/RC:C
References
- VDB-432021 | TOTOLINK CA300-PoE cstecgi.cgi setLanConfig buffer overflow vdb-entry, technical-description
- VDB-432021 | CTI Indicators (IOB, IOC, IOA) signature, permissions-required
- 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
- https://lavender-bicycle-a5a.notion.site/TOTOLINK-CA300-PoE-setLanConfig-3f953a41781f8029941cd21d2cc16db0?source=copy_link exploit
- https://www.totolink.net/ product