# CVE-2026-123958: TOTOLINK CA300-PoE buffer overflow in setLanConfig

Source: https://junglewise.ai/threats/cve-2026-123958-a-vulnerability-was-identified-in-totolink-ca300-poe-6-2c-884  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-11-07. Updated: 2026-11-07  
License: CC BY 4.0 with a link back

CVE-2026-123958 · Severity: critical · CVSS 9.9 · Published 2026-11-07

TOTOLIK CA300-PoE is a network access point that handles configuration of LAN settings. A buffer overflow vulnerability in the LAN configuration function allows remote attackers to crash the device or execute arbitrary code without requiring authentication, potentially compromising network operations and enabling unauthorized access.

Technologies: [TOTOLINK CA300-PoE](https://junglewise.ai/threats/technologies/ca300-poe). Vendors: [TOTOLINK](https://junglewise.ai/threats/vendors/totolink).

## Quick answers

**Is CVE-2026-123958 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-123958 being exploited in the wild.

**How severe is CVE-2026-123958?** Critical severity, with a CVSS score of 9.9, published 7 November 2026.

**Which products and versions are affected?** TOTOLINK CA300-PoE 6.2c.884.

**Is there a fix for CVE-2026-123958?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-123958 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-123958?** Check whether you run TOTOLINK CA300-PoE at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

A buffer overflow vulnerability exists in the setLanConfig function of /cgi-bin/cstecgi.cgi in TOTOLINK CA300-PoE 6.2c.884, triggered by manipulation of the lanDns, lanSecDns, or langType arguments. The vulnerability is remotely exploitable without authentication and allows an unauthenticated network attacker to trigger memory corruption. Exploit code is publicly available.

## Affected products

- TOTOLINK CA300-PoE 6.2c.884

## Timeline

- 2026-11-07: disclosed

## References

- [https://lavender-bicycle-a5a.notion.site/TOTOLINK-CA300-PoE-setLanConfig-3f953a41781f8029941cd21d2cc16db0?source=copy_link](https://lavender-bicycle-a5a.notion.site/TOTOLINK-CA300-PoE-setLanConfig-3f953a41781f8029941cd21d2cc16db0?source=copy_link)
- [https://vuldb.com/cve/CVE-2026-123958](https://vuldb.com/cve/CVE-2026-123958)

## Related threats

- [TOTOLINK CA300-PoE buffer overflow in UploadCustomModule](https://junglewise.ai/threats/cve-2026-124060-a-vulnerability-was-detected-in-totolink-ca300-poe-6-2c-884)
- [TOTOLINK CA300-PoE buffer overflow in WiFi configuration](https://junglewise.ai/threats/cve-2026-124059-a-security-vulnerability-has-been-detected-in-totolink-ca300-poe)
- [TOTOLINK CA300-PoE buffer overflow in WiFi repeater configuration](https://junglewise.ai/threats/cve-2026-124058-a-weakness-has-been-identified-in-totolink-ca300-poe-6-2c-884)
- [TOTOLINK CA300-PoE buffer overflow in setWiFiMultipleConfig](https://junglewise.ai/threats/cve-2026-124057-a-security-flaw-has-been-discovered-in-totolink-ca300-poe-6-2c)
- [TOTOLINK CA300-PoE buffer overflow in setWiFiBasicConfig](https://junglewise.ai/threats/cve-2026-123961-a-security-vulnerability-has-been-detected-in-totolink-ca300-poe)