Use After Free Affecting pdns-recursor package, versions [,5.2.9)[5.3.0-alpha1,5.3.6)[5.4.0-alpha1,5.4.1)
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.
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Test your applications- Snyk IDSNYK-UNMANAGED-PDNSRECURSOR-16191747
- published24 Apr 2026
- disclosed23 Apr 2026
- creditUnknown
Introduced: 23 Apr 2026
CVE-2026-33259 (opens in a new tab)How to fix?
Upgrade pdns-recursor to version 5.2.9, 5.3.6, 5.4.1 or higher.
Overview
Affected versions of this package are vulnerable to Use After Free due to concurrent modification of RPZ data. An attacker can cause inconsistent data states, trigger use-after-free conditions, or crash the process by initiating multiple simultaneous transfers of the same RPZ zone. This is only exploitable if the RPZ provider is malfunctioning and allows concurrent transfers of the same zone.