5.3

CVE-2026-42389: powerdns recursor Improper Input Validation

CVSS: 5.3v3.1MediumDeferred
AliasesUBUNTU-CVE-2026-42389DEBIAN-CVE-2026-42389
Published 25-06-2026Last modified 25-06-2026
Open JSON

Vulnerability summary

CVE-2026-42389 is a medium (CVSS 5.3) Improper Input Validation vulnerability in powerdns recursor. EPSS estimates a 0.30% chance of exploitation in the next 30 days, higher than 21.3% of scored vulnerabilities.

Overall risk
21/100
0100
Low · default modelHow is this calculated?
CVSS score
5.3/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.30%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 25-06-2026
    PublishedVulnerability first disclosed.
  2. 25-06-2026
    Last modifiedVulnerability information updated.

Description

This fix provides extra hardening for the 5.4.x branch by doing extra validation of incoming answers from authoritative servers.

CVSS metrics

4 scores · 4 sources · 1 version

EPSS trend

Probability

0.30%

Chance of exploitation in the next 30 days

Percentile

21%

Versus all other CVEs

30-day change

0.00 pp

From 0.30% on 21-09-2026

21-09-202621-10-2026
EPSS score
0.30%

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-recursor< 5.4.3-1
Powerdns1 product
Ubuntu1 product
  • pdns-recursorAll versions (No fix recorded)

3 vendors · 3 products

References

5 links