CVE-2026-5947

MEDIUM EPSS 64.9%
Published May 20, 20261mo ago · Modified Jun 17, 20262w ago
5.9 CVSS 3.1
Medium
Find Similar
Published May 20, 2026 1mo ago
Last Modified Jun 17, 2026 2w ago

Description

Undefined behavior may result due to a race condition leading to a use-after-free violation. If BIND receives an incoming DNS message signed with SIG(0), it begins work to validate that signature. If, during that validation, the "recursive-clients" limit is reached (as would occur during a query flood), and that same DNS message is discarded per the limit, there is a brief window of time while the SIG(0) validation may attempt to read the now-discarded DNS message. 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 9.18.28 through 9.18.49 and 9.18.28-S1 through 9.18.49-S1 are NOT affected.

CVSS Details

Base Score
5.9
Exploitability
2.2
Impact
3.6
Vector string
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack Vector Network
Attack Complexity High
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality None
Integrity None
Availability High

Threat Intelligence

EPSS Exploit Probability
64.9% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 2

CWE-362
CWE-416 Use After Free Memory Safety

Affected Products 2

VendorProductVersionRange
iscbind*≥9.20.0  –  <9.20.23
iscbind*≥9.21.0  –  <9.21.22

References 3

Remediation