In specific circumstances, due to a weakness in the Pseudo Random Number Generator (PRNG) that is used, it is possible for an attacker to predict the source port and query ID that BIND will use.
This issue affects BIND 9 versions 9.16.0 through 9.16.50, 9.18.0 through 9.18.39, 9.20.0 through 9.20.13, 9.21.0 through 9.21.12, 9.16.8-S1 through 9.16.50-S1, 9.18.11-S1 through 9.18.39-S1, and 9.20.9-S1 through 9.20.13-S1.
Advisories
Source ID Title
Debian DLA Debian DLA DLA-4364-1 bind9 security update
Debian DSA Debian DSA DSA-6033-1 bind9 security update
Ubuntu USN Ubuntu USN USN-7836-2 Bind vulnerabilities
Fixes

Solution

Upgrade to the patched release most closely related to your current version of BIND 9: 9.18.41, 9.20.15, 9.21.14, 9.18.41-S1, or 9.20.15-S1.


Workaround

No workarounds known.

History

Tue, 04 Nov 2025 22:30:00 +0000

Type Values Removed Values Added
References

Thu, 23 Oct 2025 10:30:00 +0000

Type Values Removed Values Added
First Time appeared Isc
Isc bind 9
Vendors & Products Isc
Isc bind 9

Thu, 23 Oct 2025 00:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-338
References
Metrics threat_severity

None

threat_severity

Important


Wed, 22 Oct 2025 18:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Wed, 22 Oct 2025 16:00:00 +0000

Type Values Removed Values Added
Description In specific circumstances, due to a weakness in the Pseudo Random Number Generator (PRNG) that is used, it is possible for an attacker to predict the source port and query ID that BIND will use. This issue affects BIND 9 versions 9.16.0 through 9.16.50, 9.18.0 through 9.18.39, 9.20.0 through 9.20.13, 9.21.0 through 9.21.12, 9.16.8-S1 through 9.16.50-S1, 9.18.11-S1 through 9.18.39-S1, and 9.20.9-S1 through 9.20.13-S1.
Title Cache poisoning due to weak PRNG
Weaknesses CWE-341
References
Metrics cvssV3_1

{'score': 8.6, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: isc

Published:

Updated: 2025-11-04T21:10:16.728Z

Reserved: 2025-04-16T08:44:49.857Z

Link: CVE-2025-40780

cve-icon Vulnrichment

Updated: 2025-11-04T21:10:16.728Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2025-10-22T16:15:42.720

Modified: 2025-11-04T22:16:11.920

Link: CVE-2025-40780

cve-icon Redhat

Severity : Important

Publid Date: 2025-10-22T00:00:00Z

Links: CVE-2025-40780 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2025-10-23T09:58:51Z