Quick answers
- Is CVE-2026-111711 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-111711 being exploited in the wild.
- How severe is CVE-2026-111711?
- Critical severity, with a CVSS score of 9.8, published 16 October 2026.
- Which products and versions are affected?
- Netcore NR256CN through 1.5.140116.
- Is there a fix for CVE-2026-111711?
- 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-2026-111711 attacked?
- It is attacked over the network, in a network appliance.
- Am I affected by CVE-2026-111711?
- Check whether you run Netcore NR256CN 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
A stack-based buffer overflow exists in the Boa web server's user_ok() function when processing HTTP Basic authentication credentials. The vulnerability occurs because the function uses unbounded strcpy() to copy the decoded username into a 64-byte stack buffer without length validation; usernames exceeding 63 bytes overflow the buffer before authentication checks are performed. An unauthenticated remote attacker can exploit this via a single HTTP request to any protected /router/*.cgi route, corrupting the stack and crashing the web server or achieving arbitrary code execution.
Affected products
- Netcore NR256CN through 1.5.140116
Timeline
- 2026-10-16: disclosed