CVE-2026-4891: dnsmasq Out-of-bounds Read
CVSS: 5.3v3.1MediumAwaiting analysis
AliasesALPINE-CVE-2026-4891UBUNTU-CVE-2026-4891DEBIAN-CVE-2026-4891CGA-4v5j-f868-3pppCGA-58w2-vgqx-v375CGA-6vfr-c5m2-pjrjCGA-x28c-48h2-4mh3
Published 11-05-2026Last modified 01-09-2026
Vulnerability summary
CVE-2026-4891 is a medium (CVSS 5.3) Out-of-bounds Read vulnerability in dnsmasq. EPSS estimates a 0.84% chance of exploitation in the next 30 days, higher than 57% of scored vulnerabilities.
CVSS score
5.3/10
010
Medium · v3.1 (CVE.org)EPSS score
0.84%
0%100%
Low · -5.58 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded
Advisory lineage
Upstream 0 · Downstream 7 · Related 4Timeline
- 11-05-2026PublishedVulnerability first disclosed.
- 01-09-2026Last modifiedVulnerability information updated.
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.
CVSS metrics
7 scores · 7 sources · 1 versionMedium 5.3Preferred score · CVE.org (CNA)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:NSources7 sources · 5.3–7.5
- OSV · AlpineEcosystem advisory · calculated5.3MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
- OSV · UbuntuEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HDiffers
- OSV · DebianEcosystem advisory · calculated5.3MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
- OSV · WolfiEcosystem advisory · calculated5.3MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
- OSV · ChainguardEcosystem advisory · calculated5.3MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
- NVDNIST5.3MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
EPSS trend
Probability
0.84%
Chance of exploitation in the next 30 days
Percentile
57%
Versus all other CVEs
30-day change
-5.58 pp
From 6.41% on 19-09-2026
19-09-202619-10-2026
EPSS score0.84%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Chainguard2 products
- dnsmasq< 2.93-r0
- dnsmasq-doc< 2.93-r0
Wolfi2 products
- dnsmasq< 2.93-r0
- dnsmasq-doc< 2.93-r0
Alpine1 product
- dnsmasq< 2.91-r1 | < 2.92_p2-r0
Debian1 product
- dnsmasq< 2.90-4~deb12u2 | < 2.91-1+deb13u1 | < 2.92-5
Dnsmasq1 product
- dnsmasq< 2.92rel2
Ubuntu1 product
- dnsmasq< 2.90-0ubuntu0.16.04.1+esm3 | < 2.90-0ubuntu0.18.04.1+esm3 | < 2.90-0ubuntu0.20.04.1+esm2 | < 2.90-0ubuntu0.22.04.3 | < 2.90-2ubuntu0.3 | < 2.91-1ubuntu0.2 | < 2.92-1ubuntu0.2
6 vendors · 8 products
