CVE-2025-7837: TOTOLINK T6 · Buffer Overflow
Affects TOTOLINK T6Source CVE Database V5
Not known to be exploited · CVSS 8.7 High.
Data as of 25 Oct 2026, 19:02 UTC
- EPSS
- 1.2% chance of exploitation in 30 days – higher than 69% 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 19 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 2026-10-25.
What to do
AI-suggested
To mitigate the risks posed by CVE-2025-7837, European organizations should: 1) Immediately identify and inventory all TOTOLINK T6 routers running the affected firmware version 4.1.5cu.748_B20211015. 3) Restrict network access to the MQTT Service port and related management interfaces by implementing firewall rules or network segmentation to limit exposure to untrusted networks, especially the internet. 4) Monitor network traffic for unusual MQTT activity or signs of exploitation attempts, using intrusion detection/prevention systems tuned for MQTT protocol anomalies. 5) Employ network-level anomaly detection to identify potential exploitation attempts targeting the recvSlaveStaInfo function. 6) Where feasible, replace vulnerable devices with models that have a stronger security track record or that receive timely security updates. 7) Educate IT staff about this vulnerability and ensure incident response plans include steps for dealing with router compromise scenarios. These measures go beyond generic advice by focusing on immediate containment, active monitoring, and vendor engagement.
Description
A vulnerability was found in TOTOLINK T6 4.1.5cu.748_B20211015 and classified as critical. Affected by this issue is the function recvSlaveStaInfo of the component MQTT Service. The manipulation of the argument dest leads to buffer overflow. The attack may be launched remotely. The exploit has been disclosed to the public and may be used.