Bug 2451298 (CVE-2026-3591)

Summary:	CVE-2026-3591 bind: BIND: Unauthorized access due to use-after-return vulnerability in DNS query handling
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	pemensik
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
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Doc Text:	A flaw was found in BIND, specifically in the named server's handling of DNS queries signed with SIG(0). A remote attacker could exploit this use-after-return vulnerability by sending a specially-crafted DNS request. This could cause an Access Control List (ACL) to improperly match an IP address, potentially leading to unauthorized access to resources.	Story Points:	---
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	2451358, 2451359, 2451573
Bug Blocks:

Description OSIDB Bzimport 2026-03-25 14:01:46 UTC

A use-after-return vulnerability exists in the `named` server when handling DNS queries signed with SIG(0). Using a specially-crafted DNS request, an attacker may be able to cause an ACL to improperly (mis)match an IP address. In a default-allow ACL (denying only specific IP addresses), this may lead to unauthorized access. Default-deny ACLs should fail-secure.
This issue affects BIND 9 versions 9.20.0 through 9.20.20, 9.21.0 through 9.21.19, and 9.20.9-S1 through 9.20.20-S1.
BIND 9 versions 9.18.0 through 9.18.46 and 9.18.11-S1 through 9.18.46-S1 are NOT affected.

Comment 2 Petr Menšík 2026-03-25 19:22:49 UTC

This bug does not affect bind component, but does affect bind9-next component in Fedora only. Bug #2440560 rebase fixes it.