CVE-2026-27854: Use after free when parsing EDNS options in Lua
An attacker might be able to trigger a use-after-free by sending crafted DNS queries to a DNSdist using the DNSQuestion:getEDNSOptions method in custom Lua code. In some cases DNSQuestion:getEDNSOptions might refer to a version of the DNS packet that has been modified, thus triggering a use-after-free and potentially a crash resulting in denial of service.
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2026-27854?
CVE-2026-27854 has a high severity rating due to the potential for use-after-free vulnerabilities in DNS queries.
How do I fix CVE-2026-27854?
To mitigate CVE-2026-27854, update your DNSdist installation to the latest version that addresses this vulnerability.
What software is affected by CVE-2026-27854?
CVE-2026-27854 affects the PowerDNS DNSdist software specifically when parsing EDNS options.
What is the impact of CVE-2026-27854 on DNSdist?
An attacker could exploit CVE-2026-27854 to potentially cause a denial of service or execute arbitrary code by sending crafted DNS queries.
When was CVE-2026-27854 disclosed?
CVE-2026-27854 was disclosed in February 2026 as part of a security advisory for DNSdist.