Use After Free Affecting unbound package, versions [1.19.1,1.25.1)
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
Do your applications use this vulnerable package?
In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.
Test your applications- Snyk IDSNYK-UNMANAGED-UNBOUND-16786629
- published21 May 2026
- disclosed20 May 2026
- creditQifan Zhang
Introduced: 20 May 2026
CVE-2026-33278 (opens in a new tab)How to fix?
Upgrade unbound to version 1.25.1 or higher.
Overview
Affected versions of this package are vulnerable to Use After Free in the DNSSEC validator process when certain DS sub-query validations fail due to NSEC3 budget exhaustion, resulting in the use of an invalid memory pointer. An attacker can cause a crash or potentially execute arbitrary code by sending specially crafted DNS responses that trigger this condition.