RHSA-2026:97486LowCVSS 4.9
Red Hat Security Advisory: dhcp security, bug fix, and enhancement update
🔗 CVE IDs covered (1)
📋 Description
CVE-2026-18103 — dhcp-server: dhcp-server: Persistent denial of service due to buffer overflow via OMAPI
🎯 Affected products35
- Red Hat Enterprise Linux BaseOS (v. 9)
- dhcp-12:4.4.2-22.b1.el9.src as a component of Red Hat Enterprise Linux BaseOS (v. 9)
- dhcp-client-12:4.4.2-22.b1.el9.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 9)
- dhcp-client-12:4.4.2-22.b1.el9.ppc64le as a component of Red Hat Enterprise Linux BaseOS (v. 9)
- dhcp-client-12:4.4.2-22.b1.el9.s390x as a component of Red Hat Enterprise Linux BaseOS (v. 9)
- dhcp-client-12:4.4.2-22.b1.el9.x86_64 as a component of Red Hat Enterprise Linux BaseOS (v. 9)
- dhcp-client-debuginfo-12:4.4.2-22.b1.el9.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 9)
- dhcp-client-debuginfo-12:4.4.2-22.b1.el9.ppc64le as a component of Red Hat Enterprise Linux BaseOS (v. 9)
- dhcp-client-debuginfo-12:4.4.2-22.b1.el9.s390x as a component of Red Hat Enterprise Linux BaseOS (v. 9)
- dhcp-client-debuginfo-12:4.4.2-22.b1.el9.x86_64 as a component of Red Hat Enterprise Linux BaseOS (v. 9)
- dhcp-common-12:4.4.2-22.b1.el9.noarch as a component of Red Hat Enterprise Linux BaseOS (v. 9)
- dhcp-debuginfo-12:4.4.2-22.b1.el9.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 9)
- dhcp-debuginfo-12:4.4.2-22.b1.el9.ppc64le as a component of Red Hat Enterprise Linux BaseOS (v. 9)
- dhcp-debuginfo-12:4.4.2-22.b1.el9.s390x as a component of Red Hat Enterprise Linux BaseOS (v. 9)
- dhcp-debuginfo-12:4.4.2-22.b1.el9.x86_64 as a component of Red Hat Enterprise Linux BaseOS (v. 9)
- dhcp-debugsource-12:4.4.2-22.b1.el9.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 9)
- dhcp-debugsource-12:4.4.2-22.b1.el9.ppc64le as a component of Red Hat Enterprise Linux BaseOS (v. 9)
- dhcp-debugsource-12:4.4.2-22.b1.el9.s390x as a component of Red Hat Enterprise Linux BaseOS (v. 9)
- dhcp-debugsource-12:4.4.2-22.b1.el9.x86_64 as a component of Red Hat Enterprise Linux BaseOS (v. 9)
- dhcp-relay-12:4.4.2-22.b1.el9.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 9)
- dhcp-relay-12:4.4.2-22.b1.el9.ppc64le as a component of Red Hat Enterprise Linux BaseOS (v. 9)
- dhcp-relay-12:4.4.2-22.b1.el9.s390x as a component of Red Hat Enterprise Linux BaseOS (v. 9)
- dhcp-relay-12:4.4.2-22.b1.el9.x86_64 as a component of Red Hat Enterprise Linux BaseOS (v. 9)
- dhcp-relay-debuginfo-12:4.4.2-22.b1.el9.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 9)
- dhcp-relay-debuginfo-12:4.4.2-22.b1.el9.ppc64le as a component of Red Hat Enterprise Linux BaseOS (v. 9)
- dhcp-relay-debuginfo-12:4.4.2-22.b1.el9.s390x as a component of Red Hat Enterprise Linux BaseOS (v. 9)
- dhcp-relay-debuginfo-12:4.4.2-22.b1.el9.x86_64 as a component of Red Hat Enterprise Linux BaseOS (v. 9)
- dhcp-server-12:4.4.2-22.b1.el9.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 9)
- dhcp-server-12:4.4.2-22.b1.el9.ppc64le as a component of Red Hat Enterprise Linux BaseOS (v. 9)
- dhcp-server-12:4.4.2-22.b1.el9.s390x as a component of Red Hat Enterprise Linux BaseOS (v. 9)
- +5 more not shown
✅ Remediation
For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 Workaround: To mitigate this issue, secure OMAPI access by configuring TSIG key authentication to prevent unauthorized connections to the OMAPI port (7911). If the `dhcpd` service has already crashed due to this flaw, manually remove the problematic InfiniBand lease entry from `/var/lib/dhcpd/dhcpd.leases` and then restart the `dhcpd` service. Restarting the `dhcpd` service may temporarily interrupt DHCP services for clients.
🔗 References (5)
- selfhttps://access.redhat.com/errata/RHSA-2026:97486
- externalhttps://docs.redhat.com/en/documentation/red_hat_enterprise_linux/9/html/9.9_release_notes/index
- externalhttps://access.redhat.com/security/updates/classification/#low
- externalhttps://bugzilla.redhat.com/show_bug.cgi?id=2508081
- selfhttps://security.access.redhat.com/data/csaf/v2/advisories/2026/rhsa-2026_97486.json