Buffer overflow in Totolink Ca300-Poe
CVE-2026-123959
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.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:H/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-setLanguageCfg-3f953a41781f… (exploit)
- vuldb.com/cve/CVE-2026-123959 (third-party-advisory)
- vuldb.com/submit/1033721 (third-party-advisory)
- vuldb.com/vuln/432022 (technical-description, vdb-entry)
- vuldb.com/vuln/432022/cti (signature, permissions-required)
- www.totolink.net/ (product, broken-link)
Frequently asked questions
- What is CVE-2026-123959?
- CVE-2026-123959 is a critical-severity vulnerability in Totolink Ca300-Poe, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 9.1/10. Published 2026-11-07.
- How severe is CVE-2026-123959?
- Critical severity. CVSS v3 base score is 9.1 out of 10.