CVE-2026-93009
Dnsmasq: dnsmasq: heap out-of-bounds read in dhcpv6 option 39 fqdn decoder
- State
- Published
- Severity
- 4.3 Medium
- Published
- Oct 29, 2026
- Updated
- Oct 30, 2026
- Reserved
- Sep 17, 2026
Description
A flaw was found in dnsmasq. The DHCPv6 client hostname parser can read one byte past the end of a crafted FQDN option because it checks the next label length before confirming the pointer is still inside the option. An attacker on the local network can trigger this with a single DHCPv6 packet. The extra byte is not returned to the client or logged, and no crash has been demonstrated.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 4.3 Medium | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N | redhat |
Weaknesses
- CWE-125 Out-of-bounds Read
Affected Products
| Product | Versions |
|---|---|
Red Hat Ceph Storage 9Red Hat | |
Red Hat Enterprise Linux 10Red Hat | |
Red Hat Enterprise Linux 6Red Hat | |
Red Hat Enterprise Linux 7Red Hat | |
Red Hat Enterprise Linux 8Red Hat | |
Red Hat Enterprise Linux 9Red Hat | |
Red Hat OpenShift Container Platform 4Red Hat | |
Red Hat OpenShift Container Platform 4Red Hat | |
Red Hat OpenShift Container Platform 4Red Hat | |
Red Hat OpenShift Container Platform 4Red Hat | |
Red Hat OpenShift Container Platform 5Red Hat | |
Red Hat OpenShift Container Platform 5Red Hat | |
Red Hat OpenStack Platform 13 (Queens)Red Hat | |
Red Hat OpenStack Platform 18.0Red Hat |
References
- https://access.redhat.com/security/cve/CVE-2026-93009vdb-entry
- RHBZ#2536083issue-tracking
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