CVE-2026-4891 (GCVE-0-2026-4891)
Vulnerability from cvelistv5 – Published: 2026-05-11 16:47 – Updated: 2026-09-01 12:04
VLAI
EPSS
VEX
Title
CVE-2026-4891
Summary
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.
Severity
5.3 (Medium)
7.5 (High)
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-05-11 18:27 UTC
CWE
- CWE-125 - Out-of-bounds Read
Assigner
References
14 references
| URL | Tags |
|---|---|
| https://lists.thekelleys.org.uk/pipermail/dnsmasq… | |
| https://www.kb.cert.org/vuls/id/471747 | |
| https://thekelleys.org.uk/dnsmasq/CVE/ | |
| https://github.com/NixOS/nixpkgs/pull/519082 | |
| https://github.com/NixOS/nixpkgs/pull/519093 | |
| https://github.com/pi-hole/FTL/releases/tag/v6.6.2 | |
| https://access.redhat.com/security/cve/CVE-2026-4891 | vdb-entryx_refsource_REDHAT |
| https://bugzilla.redhat.com/show_bug.cgi?id=2458517 | issue-trackingx_refsource_REDHAT |
| https://security.access.redhat.com/data/csaf/v2/v… | x_sadp-csaf-vex |
| https://access.redhat.com/errata/RHSA-2026:40762 | vendor-advisoryx_refsource_REDHAT |
| https://access.redhat.com/errata/RHSA-2026:19158 | vendor-advisoryx_refsource_REDHAT |
| https://access.redhat.com/errata/RHSA-2026:20589 | vendor-advisoryx_refsource_REDHAT |
| https://access.redhat.com/errata/RHSA-2026:34508 | vendor-advisoryx_refsource_REDHAT |
| https://access.redhat.com/errata/RHSA-2026:19373 | vendor-advisoryx_refsource_REDHAT |
Impacted products
8 products
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| dnsmasq | dnsmasq |
Affected:
0 , < 2.92rel2
(custom)
|
guessed | |
| Red Hat | Red Hat Enterprise Linux 10 |
Unaffected:
0:2.90-7.el10_2 , < *
(rpm)
cpe:/o:redhat:enterprise_linux:10.2 |
||
| Red Hat | Red Hat Enterprise Linux 8 |
Unaffected:
0:2.79-36.el8_10 , < *
(rpm)
cpe:/a:redhat:enterprise_linux:8 |
||
| Red Hat | Red Hat Enterprise Linux 9 |
Unaffected:
0:2.85-18.el9_8.1 , < *
(rpm)
cpe:/a:redhat:enterprise_linux:9 |
||
| Red Hat | Red Hat Enterprise Linux 9.6 Extended Update Support |
Unaffected:
0:2.85-17.el9_6.1 , < *
(rpm)
cpe:/a:redhat:rhel_eus:9.6 |
||
| Red Hat | Red Hat OpenShift Container Platform 4.19 |
Unaffected:
4.19.9.6.202607151909-0 , < *
(rpm)
cpe:/a:redhat:openshift:4.19::el9 |
||
| Red Hat | Red Hat Enterprise Linux 6 |
cpe:/o:redhat:enterprise_linux:6
|
||
| Red Hat | Red Hat Enterprise Linux 7 |
cpe:/o:redhat:enterprise_linux:7
|
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
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Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.
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