Use After Free Affecting dhcpcd package, versions <10.5.2-r0


Severity

Recommended
0.0
medium
0
10

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Threat Intelligence

EPSS
0.27% (19th percentile)

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  • Snyk IDSNYK-ALPINE323-DHCPCD-19666635
  • published10 Sept 2026
  • disclosed23 Jun 2026

Introduced: 23 Jun 2026

CVE-2026-56113  (opens in a new tab)
CWE-416  (opens in a new tab)

How to fix?

Upgrade Alpine:3.23 dhcpcd to version 10.5.2-r0 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream dhcpcd package and not the dhcpcd package as distributed by Alpine. See How to fix? for Alpine:3.23 relevant fixed versions and status.

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.

CVSS Base Scores

version 3.1