What’s Vulnerable › Vulnerabilities
CVE-2026-27853: Out-of-bounds write when rewriting large DNS packets
- Severity: high (CVSS 7.5 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.5% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2026-03-31 · updated 2026-07-25
- Weakness: CWE-787
Description
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 products
- PowerDNS DNSdist: from 1.9.0 before 1.9.12; from 2.0.0 before 2.0.3 — fixed in 1.9.12, 2.0.3
How to fix
Upgrade to a fixed version: PowerDNS DNSdist 1.9.12, 2.0.3. Check the vendor advisory for mitigations.
References
Get alerted when CVE-2026-27853 or the next vulnerability affects your stack