CVE intelligence and bounded remediation
CVE-2026-56113 — Dhcpcd Project Dhcpcd security vulnerability
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.
- Severity
- Medium
- CVSS
- 6.5 (3.1)
- Published
- 2026-06-23
- CISA KEV
- Not currently listed
- Ecosystem
- software/application
- Weaknesses
- CWE-416
Affected products
- dhcpcd_project / dhcpcd
Matched remediation archetype
Use-after-free, double free, and expired resource use
This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.
Check exposure
- Trace ownership, references, callbacks, asynchronous tasks, and teardown paths around the affected object or resource.
- Identify reachable inputs and timing or state transitions that can release the object while references remain.
- Confirm affected builds, allocators, feature flags, architectures, and process privileges.
Remediate safely
- Apply the maintained ownership or lifetime fix and rebuild all artifacts containing the affected native code.
- Use explicit ownership, safe reference management, cancellation and join semantics, and idempotent teardown.
- Add deterministic lifetime tests plus isolated sanitizer and concurrency coverage for shutdown and error paths.
Authoritative sources
Complete CVE record and remediation plan
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