CVE-2026-4891

CVE	CVE-2026-4891
State	PUBLISHED
Assigner	certcc
Source Priority	CVE Program / NVD first with legacy fallback
Published	2026-05-11 18:16:41 UTC
Updated	2026-07-02 12:17:31 UTC
Description	A heap-based out-of-bounds read vulnerability in the DNSSEC validation of dnsmasq allows remote attackers to cause a denial of service via a crafted DNS packet.

Primary CVSS: v3.1 5.3 MEDIUM from ADP

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

EPSS: 0.062260000 probability, percentile 0.926770000 (date 2026-07-04)

Problem Types: CWE-125 | CWE-125: Out-of-bounds Read | CWE-125 Out-of-bounds Read

Version	Source	Type	Score	Severity	Vector
3.1	ADP	DECLARED	5.3	MEDIUM	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N`
3.1	ADP	CVSS	7.5	HIGH	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`
3.1	134c704f-9b21-4f2e-91b3-4a467353bcc0	Secondary	5.3	MEDIUM	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N`
3.1	0b0ca135-0b70-47e7-9f44-1890c2a1c46c	Secondary	7.5	HIGH	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

None

Availability

None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Source	Vendor	Product	Version	Platforms
CNA	Dnsmasq	Dnsmasq	affected 2.92rel2 custom	Not specified
ADP	Red Hat	Red Hat Enterprise Linux AppStream V. 10	Not specified	Not specified
ADP	Red Hat	Red Hat Enterprise Linux AppStream V. 8	Not specified	Not specified
ADP	Red Hat	Red Hat Enterprise Linux AppStream EUS V.9.6	Not specified	Not specified
ADP	Red Hat	Red Hat Enterprise Linux AppStream V. 9	Not specified	Not specified
ADP	Red Hat	Red Hat Enterprise Linux 6	Not specified	Not specified
ADP	Red Hat	Red Hat Enterprise Linux 7	Not specified	Not specified
ADP	Red Hat	Red Hat OpenShift Container Platform 4	Not specified	Not specified

Reference	Source	Link	Tags
access.redhat.com/errata/RHSA-2026:34508	0b0ca135-0b70-47e7-9f44-1890c2a1c46c	access.redhat.com
access.redhat.com/security/cve/CVE-2026-4891	0b0ca135-0b70-47e7-9f44-1890c2a1c46c	access.redhat.com
access.redhat.com/errata/RHSA-2026:19373	0b0ca135-0b70-47e7-9f44-1890c2a1c46c	access.redhat.com
github.com/NixOS/nixpkgs/pull/519093	[email protected]	github.com
bugzilla.redhat.com/show_bug.cgi	0b0ca135-0b70-47e7-9f44-1890c2a1c46c	bugzilla.redhat.com
www.kb.cert.org/vuls/id/471747	[email protected]	www.kb.cert.org
thekelleys.org.uk/dnsmasq/CVE	[email protected]	thekelleys.org.uk
access.redhat.com/errata/RHSA-2026:20589	0b0ca135-0b70-47e7-9f44-1890c2a1c46c	access.redhat.com
access.redhat.com/errata/RHSA-2026:19158	0b0ca135-0b70-47e7-9f44-1890c2a1c46c	access.redhat.com
github.com/NixOS/nixpkgs/pull/519082	[email protected]	github.com
lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2026q2/018471.html	[email protected]	lists.thekelleys.org.uk
security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-4891.json	0b0ca135-0b70-47e7-9f44-1890c2a1c46c	security.access.redhat.com
github.com/pi-hole/FTL/releases/tag/v6.6.2	[email protected]	github.com
thekelleys.org.uk/dnsmasq	MITRE	thekelleys.org.uk
CVE Program record	CVE.ORG	www.cve.org	canonical
NVD vulnerability detail	NVD	nvd.nist.gov	canonical, analysis

No vendor comments have been submitted for this CVE.

Source	Time	Event
ADP	2026-04-14T22:39:35.826Z	Reported to Red Hat.
ADP	2026-05-09T00:00:00.000Z	Made public.

ADP: RHSA-2026:19158: Red Hat Enterprise Linux AppStream (v. 10)

ADP: RHSA-2026:20589: Red Hat Enterprise Linux AppStream (v. 8)

ADP: RHSA-2026:34508: Red Hat Enterprise Linux AppStream EUS (v.9.6)

ADP: RHSA-2026:19373: Red Hat Enterprise Linux AppStream (v. 9)

There are currently no legacy QID mappings associated with this CVE.