CVE-2026-3593NVD

Vulnerability Summary

A use-after-free vulnerability exists within the DNS-over-HTTPS implementation.
This issue affects BIND 9 versions 9.20.0 through 9.20.22, 9.21.0 through 9.21.21, and 9.20.9-S1 through 9.20.22-S1.
BIND 9 versions 9.18.0 through 9.18.48 and 9.18.11-S1 through 9.18.48-S1 are NOT affected.

Severity Level

HIGH(7.4)

Published Date

May 20, 2026

Last Modified

Jul 24, 2026

Exploitation Status

No confirmed exploitation yet

EPSS Score (30-Day)

1.54%Probability

Root Weakness (CWE)

CWE-416: Unknown/Unlisted Weakness ↗

Refer to the official MITRE database for detailed architectural specifications regarding this weakness.

CWE-825: Unknown/Unlisted Weakness ↗

Refer to the official MITRE database for detailed architectural specifications regarding this weakness.

CVSS v3.1 Base Metrics — Score 7.4 (HIGH)

Attack VectorNetwork

Attack ComplexityHigh

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

ConfidentialityHigh

IntegrityNone

AvailabilityHigh

Affected & Patched Versions

Affected Versions

Isc Bind >= 9.20.0 and < 9.20.23
Isc Bind >= 9.21.0 and < 9.21.22

Patched Versions

Isc Bind 9.20.23
Isc Bind 9.21.22

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