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CVE-2026-33259: powerdns recursor Use After Free

CVSS: 5.0v3.1MediumAnalyzed
AliasesUBUNTU-CVE-2026-33259DEBIAN-CVE-2026-33259
Published 22-04-2026Last modified 22-04-2026
Open JSON

Vulnerability summary

CVE-2026-33259 is a medium (CVSS 5.0) Use After Free vulnerability in powerdns recursor. EPSS estimates a 0.27% chance of exploitation in the next 30 days, higher than 18% of scored vulnerabilities.

Overall risk
20/100
0100
Low · default modelHow is this calculated?
CVSS score
5.0/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.27%
0%100%
Low · +0.04 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 22-04-2026
    PublishedVulnerability first disclosed.
  2. 22-04-2026
    Last modifiedVulnerability information updated.

Description

Having many concurrent transfers of the same RPZ can lead to inconsistent RPZ data, use after free and/or a crash of the recursor. Normally concurrent transfers of the same RPZ zone can only occur with a malfunctioning RPZ provider.

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.27%

Chance of exploitation in the next 30 days

Percentile

18%

Versus all other CVEs

30-day change

+0.04 pp

From 0.22% on 21-09-2026

21-09-202621-10-2026
EPSS score
0.27%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Debian1 product
  • pdns-recursorAll versions (No fix recorded) | < 5.2.9-0+deb13u1 | < 5.4.1-1
Powerdns1 product
  • recursor≥ 5.4.0, < 5.4.1 | ≥ 5.2.0, < 5.2.9 | ≥ 5.3.0, < 5.3.6 | 5.4.0
Ubuntu1 product
  • pdns-recursorAll versions (No fix recorded)

3 vendors · 3 products

References

5 links