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National Vulnerability Database

National Vulnerability Database

NVD

National Vulnerability Database
  1. Vulnerabilities

CVE-2026-5947 Detail

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.


Metrics

 
NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

References to Advisories, Solutions, and Tools

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URL Source(s) Tag(s)
https://downloads.isc.org/isc/bind9/9.20.23 Internet Systems Consortium (ISC)
https://downloads.isc.org/isc/bind9/9.21.22 Internet Systems Consortium (ISC)
https://kb.isc.org/docs/cve-2026-5947 Internet Systems Consortium (ISC)

Weakness Enumeration

CWE-ID CWE Name Source
CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') Internet Systems Consortium (ISC)  
CWE-416 Use After Free Internet Systems Consortium (ISC)  

Change History

1 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2026-5947
NVD Published Date:
05/20/2026
NVD Last Modified:
05/20/2026
Source:
Internet Systems Consortium (ISC)