CVE-2026-56113
MEDIUM EPSS 7.2%
Published Jun 23, 20261w ago · Modified Jun 23, 20261w ago
6.0 CVSS 4.0
Published Jun 23, 2026 1w ago
Last Modified Jun 23, 2026 1w ago
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 Details
Base Score
Exploitability
Impact
Vector string
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Attack Vector Adjacent
Attack Complexity Low
Privileges Required None
User Interaction None
Scope X
Threat Intelligence
EPSS Exploit Probability
7.2% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available
Weaknesses 1
CWE-416 Use After Free Memory Safety
References 2
- github.com https://github.com/NetworkConfiguration/dhcpcd/commit/5733d3c59a5651f64357ac11c98b4f39895c8d25
- vulncheck.com https://www.vulncheck.com/advisories/dhcpcd-heap-use-after-free-in-dhcp6-deprecateaddrs-via-dhcpv6-renew
Remediation
No remediation data recorded yet
Check vendor advisories and the NVD entry for patch availability.