CVE-2026-38821 Memory corruption in openNDS
An unauthenticated attacker can crash the openNDS daemon or potentially execute code via a heap-based buffer overflow in the captive portal network.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-38821?
CVE-2026-38821 is a high-severity memory corruption vulnerability in openNDS, published on 28 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
A heap-based buffer overflow vulnerability exists in openNDS before 11.0.0 that allows an unauthenticated attacker on the captive portal network to crash the openNDS daemon (denial of service) and potentially achieve remote code execution. This is in http_microhttpd.c.
Weakness: CWE-122
Which versions are affected by CVE-2026-38821?
How do I fix CVE-2026-38821?
No fix has been published for CVE-2026-38821 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-38821 being exploited?
There is no known exploitation of CVE-2026-38821 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-38821, GHSA-rm65-3jj4-3vcm, UBUNTU-CVE-2026-38821.