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VulnerabilityPublished

CVE-2026-33601: PowerDNS Recursor · NULL Pointer Dereference

Affects PowerDNS RecursorSource CVE Database V5

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Not known to be exploited · CVSS 4.4 Medium · fixed in 5.4.1 : update PowerDNS Recursor when convenient.

Data as of 29 Oct 2026, 19:04 UTC

CVSS 3.1 base score
4.4Medium
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.5% chance of exploitation in 30 days – higher than 43% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 5.4.1, 5.3.6, 5.2.9
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 22 Apr 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponized: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.

What to do

Upgrade Recursor and pdns-recursor to 5.4.1, 5.3.6 or 5.2.9.

Affected software

ProductAffectedFixed in
PowerDNSRecursorAffected
  • >=5.4.0 <5.4.1
Fixed in
  • 5.4.1
PowerDNSRecursorAffected
  • >=5.3.0 <5.3.6
Fixed in
  • 5.3.6
PowerDNSRecursorAffected
  • >=5.2.0 <5.2.9
Fixed in
  • 5.2.9
GitHubpdns-recursorpkg:github/pdns-recursorOther threatsAffected
  • >=5.4.0 <5.4.1
  • >=5.3.0 <5.3.6
  • >=5.2.0 <5.2.9
Fixed in
  • 5.4.1
  • 5.3.6
  • 5.2.9

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

If you cannot patch yet, users should consider restricting access to authoritative servers or monitoring for unusual DNS responses that could trigger this condition. Avoid using affected versions if possible and stay updated with PowerDNS advisories for patches.

Description

CVE-2026-33601 is a medium severity vulnerability in PowerDNS Recursor versions 5.2.0, 5.3.0, and 5.4.0. It involves a NULL pointer dereference triggered when the zoneToCache function processes a malicious authoritative server's zone data without proper consistency checks. This flaw can cause a denial of service by crashing the service. There is no confirmed patch or official remediation available at this time, and no known exploits have been reported in the wild.

References

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