CVE-2026-3593
What it is
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.
At a glance
- Exploitability
- Can be exploited over the network without logging in. High risk of data exposure, service disruption.
- Exploit odds
- 1.5% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Details
- Published
- Last modified
- Exploit probability
- 1.5% · EPSS, next 30 days
- Weakness
- CWE-416 · Use after free
- Record status
- Modified
Affected
- Isc Bind < 9.20.23
- Isc Bind < 9.21.22
Attack profile CVSS 3.1 · 7.4
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- None
- Availability
- High
Raw vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:H
Fix and advisories
- https://downloads.isc.org/isc/bind9/9.20.23
- https://downloads.isc.org/isc/bind9/9.21.22
- https://kb.isc.org/docs/cve-2026-3593
References
- https://downloads.isc.org/isc/bind9/9.20.23
- https://downloads.isc.org/isc/bind9/9.21.22
- https://kb.isc.org/docs/cve-2026-3593
- https://access.redhat.com/errata/RHSA-2026:7412
- https://access.redhat.com/security/cve/CVE-2026-3593
- https://bugzilla.redhat.com/show_bug.cgi?id=2479770
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-3593.json