CVE-2026-27853
Out-of-Bounds Write in DNSdist Lua Causes Denial of Service
Publication date: 2026-03-31
Last updated on: 2026-04-14
Assigner: Open-Xchange
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| powerdns | dnsdist | From 1.9.0 (inc) to 1.9.12 (exc) |
| powerdns | dnsdist | From 2.0.0 (inc) to 2.0.3 (exc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-787 | The product writes data past the end, or before the beginning, of the intended buffer. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability involves an attacker sending specially crafted DNS responses to a DNSdist service that uses custom Lua code with the DNSQuestion:changeName or DNSResponse:changeName methods. These crafted responses can trigger an out-of-bounds write, which means the program writes data outside the intended memory area.
In some cases, the rewritten DNS packet may become larger than the original response and can even exceed the maximum allowed size of 65535 bytes. This can cause the DNSdist service to crash.
The crash results in a denial of service condition, where legitimate users may be unable to use the DNSdist service.
How can this vulnerability impact me? :
The primary impact of this vulnerability is a denial of service (DoS) condition. An attacker exploiting this issue can cause the DNSdist service to crash by sending malicious DNS responses.
This can disrupt DNS resolution services relying on DNSdist, potentially leading to service outages or degraded network performance.