Description
A flaw was found in dhcpcd's IPv6 Neighbor Discovery Router Advertisement processing. A specially crafted IPv6 Router Advertisement containing a zero-length Neighbor Discovery option can bypass validation during packet storage and later be reparsed without adequate validation, causing the parser to enter a non-advancing loop. Successful exploitation may result in excessive CPU consumption, leading to a denial of service.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Red Hat | Red Hat Enterprise Linux 10 | — | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | dhcpcd | 1:10.2.4-3 | — |
| Debian 13 | dhcpcd | 1:10.1.0-11+deb13u4 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 25.10 | dhcpcd | No fix yet | — |
| Ubuntu 24.04 LTS | dhcpcd | No fix yet | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 10 | dhcpcd | 10.0.6-11.el10_2 | RHSA-2026:54210 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 10 | dhcpcd | 10.0.6-11.el10_2 | ALSA-2026:54210 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 10 | dhcpcd | 10.0.6-11.el10_2 | RLSA-2026:54210 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | dhcpcd | 10.0.8-4 | — |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 10 | dhcpcd | 10.0.6-11.el10_2 | ELSA-2026-54210 |
Advisories 5
- ALSA-2026:54210 Moderate: dhcpcd security update AlmaLinux Security Advisories · Oct 29, 2026
- WID-SEC-2026-2775 dhcpcd: Schwachstelle ermöglicht Denial of Service BSI CERT-Bund (WID) · Aug 16, 2026
- RLSA-2026:54210 Moderate: dhcpcd security update Rocky Linux Security Advisories · Aug 13, 2026
- RHSA-2026:54210 Red Hat Security Advisory: dhcpcd security update Red Hat Security Advisories (RHSA) · Aug 13, 2026
- ELSA-2026-54210 Moderate: dhcpcd security update (Oracle Linux 10) Oracle Linux Security Advisories (ELSA) · Aug 13, 2026