# CVE-2026-56113: dhcpcd: dhcpcd through 10.3.2, fixed in commit 5733d3c, contains a heap use-after-free vulnerability that allows unauthentica...

CVE-2026-56113 is fixed in dhcpcd on 1 platform, first by DEBIAN-CVE-2026-56113, released July 2, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-56113
- Priority: Routine
- CVSS: 6.5 (medium)
- EPSS: 0.0027
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Jun 23, 2026

## 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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | dhcpcd Debian 13.5 (trixie) | 1:10.1.0-11+deb13u3 | [DEBIAN-CVE-2026-56113](https://patchblox.com/security/data/fix/linux/debian-cve-2026-56113.md) | Jul 2, 2026 |
| Linux | dhcpcd Debian 14 | 1:10.3.2-4 | [DEBIAN-CVE-2026-56113](https://patchblox.com/security/data/fix/linux/debian-cve-2026-56113.md) | Jul 2, 2026 |
| Linux | dhcpcd opensuse-leap 16.0 | 10.5.0-160000.1.1 | [OPENSUSE-SU-2026:21692-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21692-1.md) | Aug 30, 2026 |
| Linux | dhcpcd sles 16.0 | 10.5.0-160000.1.1 | [SUSE-SU-2026:23562-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-23562-1.md) | Aug 30, 2026 |

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Data as of 2026-11-08T19:12:23Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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