How severe is CVE-2026-42389?

CVE-2026-42389 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability none.

Is CVE-2026-42389 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (7th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-42389?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-42389 have an EU (EUVD) identifier?

Yes. CVE-2026-42389 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-39388.

When was CVE-2026-42389 published?

CVE-2026-42389 was published on 2026-06-25.

CVE-2026-42389

CVE-2026-42389 is a medium-severity vulnerability with a CVSS 3.x base score of 5.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-20.

Key facts

Severity: Medium (CVSS 3.x base score 5.3)
EPSS exploit prediction: 0% (7th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-39388
Weakness: CWE-20
Published: 2026-06-25
Last modified: 2026-06-25

Description

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

Frequently asked questions

What is CVE-2026-42389?: This fix provides extra hardening for the 5.4.x branch by doing extra validation of incoming answers from authoritative servers.
How severe is CVE-2026-42389?: CVE-2026-42389 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability none.
Is CVE-2026-42389 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (7th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-42389?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-42389 have an EU (EUVD) identifier?: Yes. CVE-2026-42389 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-39388.
When was CVE-2026-42389 published?: CVE-2026-42389 was published on 2026-06-25.

References

https://docs.powerdns.com/recursor/security-advisories/powerdns-advisory-powerdns-2026-08.html

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