CVSS 4.0
8.6 highCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:PCVE-2026-123957 totolink ca300-poe: Classic Buffer Overflow
High (8.6) in totolink ca300-poe. EPSS 0.5% estimated probability of exploitation activity in the next 30 days.
On this page
A vulnerability was determined in TOTOLINK CA300-PoE 6.2c.884. Impacted is the function setIpQosRules of the file /cgi-bin/cstecgi.cgi. This manipulation of the argument ipStart causes buffer overflow. It is possible to initiate the attack remotely. The exploit has been publicly disclosed and may be utilized.
Severity
CVSS 3.1
9.9 criticalCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H- EPSS
- 0.5% estimated probability of exploitation activity in the next 30 days; 41st percentile. Scored 2026-11-13. A forecast for this CVE across the internet, not for your own systems.
- CISA's assessment (SSVC)
- Exploitation: PoC · Automatable: no · Technical impact: total, assessed 2026-11-09. From CISA's Vulnrichment in the CVE List: whether it is exploited, whether exploiting it can be automated, and how much control it gives.
- CWEs
- CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer
CWE-120 Buffer Copy without Checking Size of Input (Classic Buffer Overflow) - Published
- Modified
- NVD analysis
- Deferred: the NVD does not plan to analyze it
- Record from
- the NVD, synced
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Explain CVE-2026-123957 for an engineer deciding whether to act. Use https://cve.bz/api/public/cves/CVE-2026-123957?via=ask-ai-copy and https://cve.bz/cve/CVE-2026-123957?via=ask-ai-copy as the source of truth: what is affected and which versions fix it, whether it is in CISA KEV, public exploits, and its EPSS (an internet-wide 30-day estimate of exploitation activity, not a forecast for my systems). If they give no fixed versions, use the CVE record https://cveawg.mitre.org/api/cve/CVE-2026-123957 or the vendor advisory, not third-party mirrors. Tell me how to check whether I am affected and how to verify a fix. Cite the sources and say where they are uncertain.Opens a third-party assistant; its answer is its own, not cve.bz's. The prompt holds only this CVE's id and public links.
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Affected
Versions
From the CNA's record in the CVE List.
| Product | Affected |
|---|---|
| TOTOLINK CA300-PoE | 6.2c.884 |
Attack patterns (CAPEC)
The attack patterns MITRE's CAPEC relates to this record's weaknesses, as MITRE names them. Credits. More on the page of CWE-119 (12), CWE-120 (13).