dhcpcd Heap Use-After-Free in dhcp6_deprecateaddrs via DHCPv6 RENEW_CVE-2026-56113

6 / 10

MEDIUM

CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

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.

Basic Information

ID CVE-2026-56113

Source VulnCheck

Published Jun 23, 2026 at 16:05

Modified Jun 23, 2026 at 17:58

Affected Product

Vendor NetworkConfiguration

Product dhcpcd

Affected Versions NetworkConfiguration dhcpcd 0

CWE Classification

CWE-416

References

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    "published": "2026-06-23T16:05:59.768Z",
    "modified": "2026-06-23T17:58:21.174Z",
    "type": "cve",
    "title": "dhcpcd Heap Use-After-Free in dhcp6_deprecateaddrs via DHCPv6 RENEW",
    "source": "VulnCheck",
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