Dnsmasq: dnsmasq: out-of-bounds read in find_soa() due to missing extrabytes validation
Published Jun 23, 2026
5.3
MEDIUMCVSS 3.1
EPSS 0.40%
Description
An out-of-bounds read vulnerability exists in dnsmasq's find_soa() function in src/rfc1035.c. When parsing NS section records, extract_name() is called with extrabytes=0, failing to validate that 10 additional bytes exist for fixed-length DNS record fields. A remote attacker controlling a DNS zone can exploit this via a crafted NXDOMAIN response to cause a 10-byte heap out-of-bounds read, potentially accessing stale data from prior transactions.
Affected products
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | |||
|---|---|---|---|---|---|---|
| Red Hat | Red Hat Enterprise Linux 10 | affected |
|
Configuration 1
- 10.0
Configuration 2
- < 2.93
No data.
Red Hat Enterprise Linux 10
dnsmasq
Fix deferred
Red Hat Enterprise Linux 6
dnsmasq
Not affected
Red Hat Enterprise Linux 7
dnsmasq
Not affected
Red Hat Enterprise Linux 8
dnsmasq
Not affected
Red Hat Enterprise Linux 9
dnsmasq
Not affected
Red Hat OpenShift Container Platform 4
openshift/ose-rhel-coreos-8
Not affected
Red Hat OpenShift Container Platform 4
openshift/ose-rhel-coreos-9
Not affected
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 10 | dnsmasq | Fix deferred | n/a |
| Red Hat Enterprise Linux 6 | dnsmasq | Not affected | n/a |
| Red Hat Enterprise Linux 7 | dnsmasq | Not affected | n/a |
| Red Hat Enterprise Linux 8 | dnsmasq | Not affected | n/a |
| Red Hat Enterprise Linux 9 | dnsmasq | Not affected | n/a |
| Red Hat OpenShift Container Platform 4 | openshift/ose-rhel-coreos-8 | Not affected | n/a |
| Red Hat OpenShift Container Platform 4 | openshift/ose-rhel-coreos-9 | Not affected | n/a |
No package ranges for this CVE.
Remediation
Vendor solution
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability. The fix is available in dnsmasq 2.93rc1 and later.
Red Hat statement
Red Hat rates this issue as Low impact. While the vulnerability is remotely triggerable without authentication, the 10-byte out-of-bounds read stays within the over-allocated packet buffer in default dnsmasq configurations (1035 bytes of headroom beyond the logical packet boundary). A crash is not achievable in practice, and the potential information disclosure is limited to stale heap data within the same buffer allocation. The fix is available in dnsmasq 2.93rc1 and later.
Red Hat mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability. The fix is available in dnsmasq 2.93rc1 and later.
References (5)
- https://access.redhat.com/security/cve/CVE-2026-12969 vdb-entryx_refsource_REDHATMitigationVendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2491663 issue-trackingx_refsource_REDHATIssue TrackingVendor Advisory
- https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-38449 Advisory
- https://nvd.nist.gov/vuln/detail/CVE-2026-12969
- https://www.cve.org/CVERecord?id=CVE-2026-12969
| Link | Providers | Tags |
|---|---|---|
| https://access.redhat.com/security/cve/CVE-2026-12969 | vdb-entryx_refsource_REDHATMitigationVendor Advisory | |
| https://bugzilla.redhat.com/show_bug.cgi?id=2491663 | issue-trackingx_refsource_REDHATIssue TrackingVendor Advisory | |
| https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-38449 | Advisory | |
| https://nvd.nist.gov/vuln/detail/CVE-2026-12969 | ||
| https://www.cve.org/CVERecord?id=CVE-2026-12969 |
Change history (0)
No recorded changes yet.