Description
dhcpcd through 10.3.2, fixed in commit 5733d3c, contains a heap use-after-free vulnerability that allows unauthenticated same-link attackers to crash the daemon by sending a crafted DHCPv6 RENEW reply with RFC6603 OPTION_PD_EXCLUDE and both preferred and valid lifetimes set to zero. Attackers acting as or impersonating a DHCPv6 server can trigger dhcp6_deprecatedele() to free a delegated child address while an outer TAILQ_FOREACH_SAFE iterator in dhcp6_deprecateaddrs() still holds the freed pointer, causing a use-after-free when TAILQ_REMOVE is reached.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| NetworkConfiguration | dhcpcd | ≤ 10.3.2 | — |
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 | 1:10.3.2-4 | — |
| Debian 13 | dhcpcd | 1:10.1.0-11+deb13u3 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.04 LTS | dhcpcd | No fix yet | — |
| Ubuntu 25.10 | dhcpcd | No fix yet | — |
| Ubuntu 24.04 LTS | dhcpcd | No fix yet | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | dhcpcd | 10.5.0-160000.1.1 | SUSE-SU-2026:23562-1 |
| SLES 16.0 | dhcpcd | 10.5.0-160000.1.1 | SUSE-SU-2026:23562-1 |
| SLE Micro 6.2 | dhcpcd | 10.5.0-160000.1.1 | SUSE-SU-2026:23400-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | dhcpcd | 10.5.0-1.1 | openSUSE-SU-2026:11473-1 |
| openSUSE Leap 16.0 | dhcpcd | 10.5.0-160000.1.1 | openSUSE-SU-2026:21692-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | dhcpcd | 10.5.2-r0 | — |
| Alpine v3.23 | dhcpcd | 10.5.2-r0 | — |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | dhcpcd | 10.0.8-4 | — |
Advisories 5
- WID-SEC-2026-2046 dhcpcd: Mehrere Schwachstellen ermöglichen Denial of Service BSI CERT-Bund (WID) · Oct 29, 2026
- SUSE-SU-2026:23562-1 Security update for dhcpcd SUSE / openSUSE Security Updates · Sep 29, 2026
- SUSE-SU-2026:23400-1 Security update for dhcpcd SUSE / openSUSE Security Updates · Sep 10, 2026
- openSUSE-SU-2026:21692-1 Security update for dhcpcd SUSE / openSUSE Security Updates · Aug 31, 2026
- openSUSE-SU-2026:11473-1 dhcpcd-10.5.0-1.1 on GA media SUSE / openSUSE Security Updates · Aug 10, 2026