Vulnerability · Published Jun 23, 2026 · Assigned by VulnCheck
CVE-2026-56113dhcpcd Heap Use-After-Free in dhcp6_deprecateaddrs via DHCPv6 RENEW
Medium 5.3
In plain English
A medium-severity use-after-free in dhcpcd from NetworkConfiguration. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 19% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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 packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.23 | dhcpcd | 10.5.2-r0 | ALPINE-CVE-2026-56113 |
| Alpine:v3.24 | dhcpcd | 10.5.2-r0 | ALPINE-CVE-2026-56113 |
| Debian:13 | dhcpcd | 1:10.1.0-11+deb13u3 | DEBIAN-CVE-2026-56113 |
| Debian:14 | dhcpcd | 1:10.3.2-4 | DEBIAN-CVE-2026-56113 |
| Ubuntu:24.04:LTS | dhcpcd | no fix listed | UBUNTU-CVE-2026-56113 |
| Ubuntu:25.10 | dhcpcd | no fix listed | UBUNTU-CVE-2026-56113 |
| Ubuntu:26.04:LTS | dhcpcd | no fix listed | UBUNTU-CVE-2026-56113 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| NetworkConfiguration | dhcpcd | 0 – through 10.3.2 |
Weakness: CWE-416 · Vector: CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H