PatchSiren cyber security CVE debrief
CVE-2026-11523 Tenda CVE debrief
A stack-based buffer overflow vulnerability has been discovered in Tenda W20E version 15.11.0.6. The issue affects the `formPortalAuth` function located in the `/goform/PortalAuth` file of the Web Management Interface. An attacker can exploit this vulnerability remotely by manipulating the `gotoUrl` argument, leading to a potential stack-based buffer overflow. The Common Vulnerability Scoring System (CVSS) score for this vulnerability is 7.4, indicating a HIGH severity level. The vulnerability was published on [cve-org](https://www.cve.org/CVERecord?id=CVE-2026-11523) and additional details can be found on [nvd](https://nvd.nist.gov/vuln/detail/CVE-2026-11523).
- Vendor
- Tenda
- Product
- W20E
- CVSS
- HIGH 7.4
- CISA KEV
- Not listed in stored evidence
- Original CVE published
- 2026-06-08
- Original CVE updated
- 2026-06-09
- Advisory published
- 2026-06-08
- Advisory updated
- 2026-06-09
Who should care
Administrators and users of Tenda W20E version 15.11.0.6 should be aware of this vulnerability and take necessary precautions to mitigate the risk.
Technical summary
The vulnerability is caused by a stack-based buffer overflow in the `formPortalAuth` function of the `/goform/PortalAuth` file. This can be exploited remotely by an attacker manipulating the `gotoUrl` argument.
Defensive priority
HIGH
Recommended defensive actions
- Update to the latest version of Tenda W20E if available.
- Restrict access to the Web Management Interface.
- Monitor network traffic for suspicious activity.
Evidence notes
The vulnerability has been published and an exploit may be available. See [ref-4](https://github.com/Robots10/IoT_vlu/blob/main/reports/Tenda/formPortalAuth/formPortalAuth.md) for more information.
Official resources
CVE-2026-11523 was published on 2026-06-08T16:16:37.113Z and modified on 2026-06-09T01:34:33.987Z.