Quick answers
- Is CVE-2026-38577 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-38577 being exploited in the wild.
- How severe is CVE-2026-38577?
- Critical severity, with a CVSS score of 9.8, published 31 August 2026.
- Which products and versions are affected?
- Tenda HG21 V4.0.0-260302.
- Is there a fix for CVE-2026-38577?
- 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-2026-38577 attacked?
- It is attacked over the network, in a network appliance.
- Am I affected by CVE-2026-38577?
- Check whether you run Tenda HG21 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
This vulnerability stems from hardcoded administrative credentials embedded in the firmware of Tenda HG21 routers running version V4.0.0-260302. The Admin account contains fixed, publicly discoverable credentials that cannot be changed through normal configuration, allowing any networked attacker to authenticate and gain root-level access to the device. The attack requires only network reachability to the management interface and no user interaction or authentication bypass techniques. An attacker can leverage this access to modify firewall rules, install malware, perform man-in-the-middle attacks, or compromise the entire network behind the affected router. Patches or firmware updates addressing this issue have not been confirmed at this time.
Affected products
- Tenda HG21 V4.0.0-260302
Timeline
- 2026-08-31: disclosed