CVE-2025-7758: TOTOLINK T6 · Buffer Overflow
Affects TOTOLINK T6Source CVE Database V5
Not known to be exploited · CVSS 8.7 High.
Data as of 26 Oct 2026, 06:26 UTC
- EPSS
- 0.9% chance of exploitation in 30 days – higher than 62% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:PExploitation evidence
Disclosed: evidence found.
CVE published 17 Jul 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-26.
What to do
AI-suggested
1. Immediate firmware update: TOTOLINK users should verify the availability of a patched firmware version from the vendor and apply it promptly. 2. Network segmentation: Isolate vulnerable TOTOLINK T6 devices from critical network segments to limit potential lateral movement in case of compromise. 3. Access control: Restrict remote management access to the router’s web interface by disabling WAN-side administration or limiting access via firewall rules to trusted IP addresses only. 4. Intrusion detection: Deploy network intrusion detection systems (NIDS) capable of detecting anomalous HTTP POST requests targeting /cgi-bin/cstecgi.cgi or unusual traffic patterns indicative of exploitation attempts. 5. Device replacement: For environments where patching is not feasible or timely, consider replacing affected devices with routers from vendors with robust security update practices. 6. User awareness: Educate users about the risks of using outdated router firmware and encourage regular updates and security hygiene.
Description
A vulnerability, which was classified as critical, has been found in TOTOLINK T6 up to 4.1.5cu.748_B20211015. Affected by this issue is the function setDiagnosisCfg of the file /cgi-bin/cstecgi.cgi of the component HTTP POST Request Handler. The manipulation of the argument ip leads to buffer overflow. The attack may be launched remotely. The exploit has been disclosed to the public and may be used.