CVE-2026-5172
A public proof of concept exists; no exploitation attested.
- Published2026-05-11
- WeaknessCWE-125
Am I affected?
Debian, Ubuntu or Red Hat sometimes backport a fix without changing the upstream version number: such a version reads « to verify », never « affected ».With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.
Description
A buffer overflow in dnsmasq’s extract_addresses() function allows an attacker to trigger a heap out-of-bounds read and crash by exploiting a malformed DNS response, enabling extract_name() to advance the pointer past the record’s end.
Timeline
dates in UTC- 2026-05-1118:16CVE publishedNVD
Observed activity
isMalicious corpus · updated 2026-10-23 21:37 UTCBlock these indicators
- Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2026-5172?format=txt
- CSV export: https://api.ismalicious.com/edl/cve/CVE-2026-5172?format=csv
- TAXII collection of exploited CVEs
- The EDL and CSV take an API key on the Pro plan.
Versions per branch
Distribution builds and vendor advisories
Packages from OSV.dev and products from the vendors' CSAF advisories.
version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.
Packages
- dnsmasqAlmaLinux:10all versions · fixed in 2.90-7.el10_2and 1 other package
Vendor advisories
dnsmasq: extract_addresses() OOB read via malformed rdlen
dnsmasq as a component of Red Hat Enterprise Linux 6 · dnsmasq-utils as a component of Red Hat Enterprise Linux 6 · dnsmasq.src as a component of Red Hat Enterprise Linux 6 · +7 more
Red Hat Security Advisory: dnsmasq security update
Fix
- Vendor fix Red Hat Product Security RHSA-2026:19158 · 21 productsFor details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258
- No fix available, says the vendor Red Hat Product Security CVE-2026-5172 · 1 productAffected
- No fix planned, says the vendor Red Hat Product Security CVE-2026-5172 · 3 productsOut of support scope
- No fix planned, says the vendor Red Hat Product Security CVE-2026-5172 · 6 productsWill not fix
Detection
read 2026-10-23 19:25 UTC- Nuclei template
- none so far ProjectDiscovery
- Exploit-DB
- no entry Exploit-DB
Sources
- NVDCVE recordread 2026-10-23
- CISA-ADPSSVC decisionnone2026-05-13
- OpenCVESSVC decisionnone—
- CISA-ADPCVSS 3.17.32026-05-13
- CNACVSS 3.17.5read 2026-10-23
- CNAweakness (CWE)CWE-125read 2026-10-23
- FIRST EPSSEPSS score0.7 %2026-10-23
- PoC-in-GitHubproof of concept1read 2026-10-23
- OSVaffected packages—
- Microsoft MSRCadvisory—
Technical details
- CVSS v3 Vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Published
- 2026-05-11
- Last Modified
- 2026-08-24
- NVD status
- Awaiting Analysis
- MSRC Title
- CVE-2026-5172
Frequently asked questions
What is CVE-2026-5172?
Is CVE-2026-5172 actively exploited?
What is the CVSS score for CVE-2026-5172?
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Related vulnerabilities
Same product first, then the same vendor advisory and the same publication week.