A heap-based out-of-bounds read vulnerability in the DNSSEC validation of dnsmasq allows…
Priority LOW 33Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- Low · None · None
- Fix status
- Partial Red Hat: 8 fixed, 2 without a fix
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA and Red Hat.
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.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.06411 93rd percentileScored 2026-11-07
Fix Partial dnsmasq (dnsmasq): 2.92rel2Red Hat: 8 advisoriesRed Hat: 8 fixed, 2 without a fix
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
- Fix · CNA dnsmasq (dnsmasq) Fixed in 2.92rel2
Red Hat 8 advisories
- RHSA-2026:95088 Released 2026-11-04 · Red Hat rating Importantdnsmasq security, bug fix, and enhancement update
- Red Hat Enterprise Linux AppStream E4S (v.9.4) dnsmasq-2.85-16.el9_4.1
- RHSA-2026:95093 Released 2026-11-04 · Red Hat rating Importantdnsmasq security, bug fix, and enhancement update
- Red Hat Enterprise Linux AppStream E4S (v.9.2) dnsmasq-2.85-6.el9_2.5
- RHSA-2026:92677 Released 2026-10-29 · Red Hat rating Importantdnsmasq security, bug fix, and enhancement update
- Red Hat Enterprise Linux AppStream EUS (v. 10.0) dnsmasq-2.90-4.el10_0.1
Show 5 more Red Hat advisories
- RHSA-2026:40762 Released 2026-07-22 · Red Hat rating ImportantOpenShift Container Platform 4.19.39 bug fix and security update
- Red Hat OpenShift Container Platform 4.19 rhcos-aarch64-4.19.9.6.202607151909-0, rhcos-ppc64le-4.19.9.6.202607151909-0, rhcos-s390x-4.19.9.6.202607151909-0 +1
- RHSA-2026:34508 Released 2026-07-01 · Red Hat rating Importantdnsmasq security update
- Red Hat Enterprise Linux AppStream EUS (v.9.6) dnsmasq-2.85-17.el9_6.1, dnsmasq-utils-2.85-17.el9_6.1
- RHSA-2026:20589 Released 2026-05-26 · Red Hat rating Importantdnsmasq security update
- Red Hat Enterprise Linux AppStream (v. 8) dnsmasq-2.79-36.el8_10, dnsmasq-utils-2.79-36.el8_10
- RHSA-2026:19373 Released 2026-05-19 · Red Hat rating Importantdnsmasq security update
- Red Hat Enterprise Linux AppStream (v. 9) dnsmasq-2.85-18.el9_8.1, dnsmasq-utils-2.85-18.el9_8.1
- RHSA-2026:19158 Released 2026-05-19 · Red Hat rating Importantdnsmasq security update
- Red Hat Enterprise Linux AppStream (v. 10) dnsmasq-2.90-7.el10_2, dnsmasq-utils-2.90-7.el10_2
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Release ·
dnsmasq 2.92rel2
6 records Highest priority Priority MEDIUM 2 MEDIUM, 4 LOW
Other records, highest priority first
- TI-2026-04261 A Denial of Service (DoS) vulnerability in the DNSSEC validation of dnsmasq allows remote…Priority MEDIUM 50
- TI-2026-04263 A heap-based out-of-bounds write vulnerability in the DHCPv6 implementation of dnsmasq…Priority MEDIUM 40
- TI-2026-04515 A buffer overflow in dnsmasq’s extract_addresses() function allows an attacker to trigger…Priority LOW 37
Vendor assessments
Red Hat
Red Hat rating: Important. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Will not fix |
| Red Hat OpenShift Container Platform 4 | Affected | No fix yet |
| Red Hat Enterprise Linux AppStream (v. 10) | Fixed | RHSA-2026:19158 |
| Red Hat Enterprise Linux AppStream (v. 8) | Fixed | RHSA-2026:20589 |
| Red Hat Enterprise Linux AppStream (v. 9) | Fixed | RHSA-2026:19373 |
| Red Hat Enterprise Linux AppStream E4S (v.9.2) | Fixed | RHSA-2026:95093 |
| Red Hat Enterprise Linux AppStream E4S (v.9.4) | Fixed | RHSA-2026:95088 |
| Red Hat Enterprise Linux AppStream EUS (v. 10.0) | Fixed | RHSA-2026:92677 |
| Red Hat Enterprise Linux AppStream EUS (v.9.6) | Fixed | RHSA-2026:34508 |
| Red Hat OpenShift Container Platform 4.19 | Fixed | RHSA-2026:40762 |
Not affected: 4 products
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux AppStream E4S (v.9.2)
- Red Hat Enterprise Linux AppStream E4S (v.9.4)
- Red Hat Enterprise Linux AppStream EUS (v. 10.0)
Timeline
- 2026-10-02 Threatist record created from CVE-2026-4891
- 2026-10-03 Alias added: GHSA-2qp9-xr4x-2cr9
- 2026-10-25 EPSS moved to the 90th–95th percentile
- 2026-10-30 Fix available: Red Hat Enterprise Linux AppStream EUS (v. 10.0) · Red Hat
- 2026-10-30 Fix available: RHSA-2026:92677 · Red Hat
- 2026-10-30 Affected versions changed · Red Hat
- 2026-11-04 Fix available: RHSA-2026:95088 · Red Hat
- 2026-11-04 Fix available: RHSA-2026:95093 · Red Hat
- 2026-11-04 Fix available: Red Hat Enterprise Linux AppStream E4S (v.9.2), Red Hat Enterprise Linux AppStream E4S (v.9.4) · Red Hat
References
More dnsmasq vulnerabilities
- TI-2020-19262 dnsmasq-utils 2.79-1 - 'dhcp_release' Denial of Service CVSS 4.0MEDIUM 6.9
- TI-2026-04261 A Denial of Service (DoS) vulnerability in the DNSSEC validation of dnsmasq allows remote… CVSS 3.1HIGH 7.5
- TI-2026-04263 A heap-based out-of-bounds write vulnerability in the DHCPv6 implementation of dnsmasq… CVSS 3.1HIGH 8.4
- TI-2026-04515 A buffer overflow in dnsmasq’s extract_addresses() function allows an attacker to trigger… CVSS 3.1HIGH 7.3
- TI-2026-04264 An information disclosure vulnerability in dnsmasq allows remote attackers to bypass… CVSS 3.1MEDIUM 5.3
- TI-2026-01936 dnsmasqs extract_name() function can be abused to cause a heap buffer overflow, allowing… CVSS 3.1HIGH 7.3
Sources
- CVE-2026-4891 · CVE Program
- CVE-2026-4891 · NVD
- FIRST EPSS
- GHSA-2qp9-xr4x-2cr9 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-4891 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences