CVE-2026-27853: Out-of-bounds write when rewriting large DNS packets
An attacker might be able to trigger an out-of-bounds write by sending crafted DNS responses to a DNSdist using the DNSQuestion:changeName or DNSResponse:changeName methods in custom Lua code. In some cases the rewritten packet might become larger than the initial response and even exceed 65535 bytes, potentially leading to a crash resulting in denial of service.
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2026-27853?
CVE-2026-27853 is considered a high severity vulnerability due to the potential for remote code execution through crafted DNS responses.
How do I fix CVE-2026-27853?
To fix CVE-2026-27853, update to the latest version of PowerDNS DNSdist that contains the security patch addressing this vulnerability.
What causes the vulnerability CVE-2026-27853?
CVE-2026-27853 is caused by an out-of-bounds write that occurs when handling large DNS packets in custom Lua scripts within DNSdist.
What impact can CVE-2026-27853 have on my system?
Exploiting CVE-2026-27853 can lead to denial of service or remote code execution, potentially compromising the DNS service.
Who is affected by CVE-2026-27853?
CVE-2026-27853 affects users of PowerDNS DNSdist that utilize the DNSQuestion:changeName or DNSResponse:changeName methods in Lua.