Vulnerability 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.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Dhcpcd Project | Dhcpcd | <= 10.3.2 |
Related Weaknesses (CWE)
References
- https://github.com/NetworkConfiguration/dhcpcd/commit/5733d3c59a5651f64357ac11c9Patch
- https://www.vulncheck.com/advisories/dhcpcd-heap-use-after-free-in-dhcp6-deprecaThird Party Advisory
FAQ
What is CVE-2026-56113?
CVE-2026-56113 is a vulnerability with a CVSS score of 5.3 (MEDIUM). 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...
How severe is CVE-2026-56113?
CVE-2026-56113 has been rated MEDIUM with a CVSS base score of 5.3/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-56113?
Check the references section above for vendor advisories and patch information. Affected products include: Dhcpcd Project Dhcpcd.