CVE-2026-27831 rldns Vulnerable to Heap-based Out-of-Bounds Read
An attacker can cause a denial of service in the rldns DNS server via a heap-based out-of-bounds read vulnerability.
- 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-2026-27831?
CVE-2026-27831 is a high-severity memory corruption vulnerability in bluedragonsecurity rldns, published on 26 Feb 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
rldns is an open source DNS server. Version 1.3 has a heap-based out-of-bounds read that leads to denial of service. Version 1.4 contains a patch for the issue.
Weakness: CWE-125
Which versions are affected by CVE-2026-27831?
How do I fix CVE-2026-27831?
No fix has been published for CVE-2026-27831 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-2026-27831 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-27831 exists.
Public exploit code: 1 proofs of concept on GitHub.