Stale heap disclosure via unchecked DNS fields
Published Jun 23, 2026 · Updated Jun 23, 2026
Out-of-bounds read in dnsmasq on Red Hat Enterprise Linux 10 allows remote attackers to expose stale heap data via a crafted DNS response. In find_soa() in src/rfc1035.c, extract_name() receives extrabytes=0 for NS records, so fixed-field reads consume 10 bytes beyond the logical packet. Exploitation requires control of a queried DNS zone; default buffer headroom prevents a practical crash and confines disclosure to stale data in the same allocation.
Summary
What happened
Out-of-bounds read in dnsmasq on Red Hat Enterprise Linux 10 allows remote attackers to expose stale heap data via a crafted DNS response. In find_soa() in src/rfc1035.c, extract_name() receives extrabytes=0 for NS records, so fixed-field reads consume 10 bytes beyond the logical packet. Exploitation requires control of a queried DNS zone; default buffer headroom prevents a practical crash and confines disclosure to stale data in the same allocation.
The record
- CVE
- CVE-2026-12969
- Published
- Jun 23, 2026
- Updated
- Jun 23, 2026
- Vendor
- 389 Directory Server
- Product
- Red Hat Enterprise Linux 10
- Classifications
- CWE-125
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jun 23, 2026CVE publishedPublication date reported by the CVE source.
- Jun 23, 2026Record updatedLatest update available in the CVE record.
Exploitability
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What is affected?
Published CVSS scores
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Attacks
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Weakness, pattern, technique
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Technologies
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