Vulnerability · Published Nov 7, 2026 · Assigned by VulDB
CVE-2026-123959TOTOLINK CA300-PoE cstecgi.cgi setLanguageCfg buffer overflow
Critical 9.1
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)9.1Critical
Exploit odds (30 days)–no EPSS score yet
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known
Official description
A security flaw has been discovered in TOTOLINK CA300-PoE 6.2c.884. The impacted element is the function setLanguageCfg of the file /cgi-bin/cstecgi.cgi. Performing a manipulation of the argument langType results in buffer overflow. The attack can be initiated remotely. The exploit has been released to the public and may be used for attacks.
Affected products (as reported)
Weakness: CWE-120, CWE-119 · Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H/E:P/RL:X/RC:C
References
- VDB-432022 | TOTOLINK CA300-PoE cstecgi.cgi setLanguageCfg buffer overflow vdb-entry, technical-description
- VDB-432022 | CTI Indicators (IOB, IOC, IOA) signature, permissions-required
- CVE-2026-123959 | CVE Analysis and Report third-party-advisory
- Submit #1033721 | TOTOLINK CA300-PoE CA300-PoE_Firmware V6.2c.884 Buffer Overflow third-party-advisory
- https://lavender-bicycle-a5a.notion.site/TOTOLINK-CA300-PoE-setLanguageCfg-3f953a41781f80199f44f227136a1441?source=copy_link exploit
- https://www.totolink.net/ broken-link, product