CVE-2026-51739 Missing authorization in n/a
Unauthenticated attackers can bypass access controls to trigger cloud update checks on TOTOLINK T6 routers via crafted POST requests.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-51739?
CVE-2026-51739 is a medium-severity missing authorization vulnerability in n/a, published on 31 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Incorrect access control in the CloudSrvVersionCheck function of TOTOLINK T6 4.1.5cu.748_B20211015 allows unauthenticated attackers to trigger cloud update checks via sending a crafted POST request to /cgi-bin/cstecgi.cgi.
Weakness: CWE-284
Which versions are affected by CVE-2026-51739?
How do I fix CVE-2026-51739?
No fix has been published for CVE-2026-51739 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-51739 being exploited?
There is no known exploitation of CVE-2026-51739 in the wild and no public exploit code.
Sources
Also known as GHSA-5jxr-hwh6-cf5p.