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Enterprise LinuxOperating system · Redhat

CVE-2026-12969

MEDIUM · 5.3 CVSS v3.1 Published 2026-06-23
Fix available
A fix is available. Upgrade to 2.93 or later.
See remediation →
62/100
Remediation priority · Elevated
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

An out-of-bounds read vulnerability exists in dnsmasq's find_soa() function where extract_name() is called with extrabytes=0 when parsing NS section records, 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 heap allocations.

MitigationUpgrade dnsmasq to the patched version that adds proper bounds validation in extract_name() to ensure sufficient bytes exist before reading fixed-length DNS record fields. As a defensive measure, restrict authoritative DNS servers that the dnsmasq instance accepts responses from to trusted sources.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Enterprise LinuxOperating system
Affected:= 10.0
DnsmasqApplication
Affected:< 2.93

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check if dnsmasq is installed
    Run 'dnsmasq --version' or use your package manager to query the dnsmasq package (e.g., 'rpm -q dnsmasq' on RHEL, 'dpkg -l dnsmasq' on Debian)
    Affected if dnsmasq is installed on the system
  2. Identify the installed dnsmasq version
    Run 'dnsmasq --version' and note the version number displayed in the output
    Affected if version is less than 2.93 (e.g., 2.92, 2.91, etc.)
  3. Verify if dnsmasq service is running
    Run 'systemctl status dnsmasq' or 'ps aux | grep dnsmasq' to check if the dnsmasq process is active
    Affected if dnsmasq is currently running as a daemon (the vulnerability triggers when processing DNS responses)
  4. Confirm the system is using dnsmasq as a DNS resolver
    Check /etc/resolv.conf to see if dnsmasq is listed as a nameserver, or check dnsmasq config in /etc/dnsmasq.conf for listen-address settings
    Affected if the system relies on dnsmasq for DNS resolution (the vulnerability is triggered when parsing DNS responses from upstream servers)

You are affected if dnsmasq version less than 2.93 is installed and running as an active DNS service handling responses from upstream servers.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 2.93 or later
Fixed in 2.93
Interim mitigation

Upgrade dnsmasq to the patched version that adds proper bounds validation in extract_name() to ensure sufficient bytes exist before reading fixed-length DNS record fields. As a defensive measure, restrict authoritative DNS servers that the dnsmasq instance accepts responses from to trusted sources.

Recommended fix High confidence

dnsmasq >= 2.93

  1. Verify current dnsmasq version by running 'dnsmasq --version'
  2. Check for available updates via 'dnsmasq --version' and compare against fixed release 2.93
  3. Update dnsmasq package using the system package manager (e.g., 'dnf update dnsmasq' on RHEL-based systems)
  4. After updating, restart the dnsmasq service to load the fixed version
  5. Verify the installed version is >= 2.93 using 'dnsmasq --version'
Caveat Minor: Ensure any custom dnsmasq configuration is compatible with the new version before production deployment

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Enterprise Linux Scoped from the published advisory
  • Consultation2.0 h
  • Implementation3.0 h
  • Testing4.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,900
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-12969 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data