How severe is CVE-2026-40208?

CVE-2026-40208 has a CVSS 3.x base score of 3.7, rated low severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability low.

Is CVE-2026-40208 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (20th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-40208?

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

Does CVE-2026-40208 have an EU (EUVD) identifier?

Yes. CVE-2026-40208 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-39347.

When was CVE-2026-40208 published?

CVE-2026-40208 was published on 2026-06-25.

CVE-2026-40208

CVE-2026-40208 is a low-severity vulnerability with a CVSS 3.x base score of 3.7. 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-705.

Key facts

Severity: Low (CVSS 3.x base score 3.7)
EPSS exploit prediction: 0% (20th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-39347
Weakness: CWE-705
Published: 2026-06-25
Last modified: 2026-06-25

Description

An attacker might be able to delay the processing of DoH3 queries by sending DoH3 GET queries with an invalid DATA frame.

Frequently asked questions

What is CVE-2026-40208?: An attacker might be able to delay the processing of DoH3 queries by sending DoH3 GET queries with an invalid DATA frame.
How severe is CVE-2026-40208?: CVE-2026-40208 has a CVSS 3.x base score of 3.7, rated low severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability low.
Is CVE-2026-40208 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (20th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-40208?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-40208 have an EU (EUVD) identifier?: Yes. CVE-2026-40208 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-39347.
When was CVE-2026-40208 published?: CVE-2026-40208 was published on 2026-06-25.

References

https://www.dnsdist.org/security-advisories/powerdns-advisory-for-dnsdist-2026-09.html

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