synced 3 MIN AGO
01 Record

CVE-2026-3593

Heap use-after-free vulnerability in BIND 9 DNS-over-HTTPS implementation

HighPUBLISHEDCNA: isc
CNA base score7.4 CVSS v3.xCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:H

02 Description

Heap use-after-free vulnerability in BIND 9 DNS-over-HTTPS implementation

03 Exploitation and scoring

Exploitation
Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.
SSVC decision
  • ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
  • AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
  • Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.
CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.
EPSS probability
1.53% probability of exploitation activity in the next 30 days.
EPSS percentile
Equal to or higher than the score of 74.7% of scored records. A rank, not a probability.
NVD base score
9.8 (CVSS v3.x), scored by the NVD independently of the CNA.
NVD CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD analysis status
Modified. NVD last modified this record on 2026-08-24.
Red Hat severity
Important. Red Hat's rating for its own products, not a CVSS rating.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

04 Metadata

Published
2026-05-20 13:09Z5 MO AGO
Last updated
2026-09-01 12:04Z1 MO AGO
Reserved
2026-03-05
Assigning CNA
isc
Record state
PUBLISHED
Severity
High (CVSS 7.4)
CNA CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:H
Weaknesses
Data version
5.2
Document digest
0f22d2dbfe6580abea1d95dd9ace3e4081765cc0d5cc70c3c14523fbc9ce60dc

05 Affected products

VendorProductVersionsPlatforms
ISCBIND 99.20.0 to 9.20.22, 9.21.0 to 9.21.21, 9.20.9-S1 to 9.20.22-S1—

06 References

07 Remediation

Upgrade to the patched release most closely related to your current version of BIND 9: 9.20.23, 9.21.22, or 9.20.23-S1.

08 Fixed in

Debian 13

  • bind9
    Fixed in 1:9.20.23-1~deb13u1

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Debian 14

  • bind9
    Fixed in 1:9.20.23-1

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 25.10

  • bind9
    Fixed in 1:9.20.11-1ubuntu2.4

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 26.04 LTS

  • bind9
    Fixed in 1:9.20.18-1ubuntu2.1

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

A release or ecosystem missing from this list has no record here. It may be unaffected or not covered by the source. Source notices and licences.