Bug 2491841 (CVE-2026-56113) - CVE-2026-56113 dhcpcd: dhcpcd: Denial of Service via crafted DHCPv6 RENEW reply
Summary: CVE-2026-56113 dhcpcd: dhcpcd: Denial of Service via crafted DHCPv6 RENEW reply
Keywords:
Status: NEW
Alias: CVE-2026-56113
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security
QA Contact:
URL:
Whiteboard:
Depends On: 2492034 2492035
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-06-23 17:05 UTC by OSIDB Bzimport
Modified: 2026-06-23 22:45 UTC (History)
2 users (show)

Fixed In Version:
Clone Of:
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Last Closed:
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Description OSIDB Bzimport 2026-06-23 17:05:25 UTC 
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.
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