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CVE-2026-56113

dhcpcd Heap Use-After-Free in dhcp6_deprecateaddrs via DHCPv6 RENEW

Published: Jun 23, 2026Updated: Jul 14, 2026 Sources: CVE List NVDCWE-416
5.3MEDIUM
NVD MITRE
EPSS Score
0.2%
Top 92.7%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
Patch Available
Self-Check
Not available

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.

No summary for this CVE yet.

CVSS Vector Breakdown

AV:AAC:HPR:NUI:NS:UC:NI:NA:H
Exploitability
AV:AAttack Vector
Adjacent
AC:HAttack Complexity
High
PR:NPrivileges Required
None
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:NConfidentiality
None
I:NIntegrity
None
A:HAvailability
High
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Weaknesses

CWE-416

Affected Products

dhcpcd project
oss-projectaka dhcpcd
dhcpcdOn-prem
Networking Infrastructure / dns-dhcp-ntp
NetworkConfiguration
oss-project
dhcpcdLibrary
Networking Infrastructure / dns-dhcp-ntp

Exploitability

Official Patch Available

Attack Graph

Products CVE Techniques Tactics

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MITRE ATT&CK

2 techniques
Initial Access
Privilege Escalation
View detailed technique mapping

References

https://github.com/NetworkConfiguration/dhcpcd/commit/5733d3c59a5651f64357ac11c98b4f39895c8d25
github.com
https://www.vulncheck.com/advisories/dhcpcd-heap-use-after-free-in-dhcp6-deprecateaddrs-via-dhcpv6-renew
vulncheck.com

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