Description
In DragonFly BSD through 6.4.2 before 4bb22ff, the ARP input handlers arpintr() and in_arpinput() (sys/netinet/if_ether.c) do not validate the hardware address length (ar_hln) and protocol address length (ar_pln) fields of incoming ARP packets. in_arpreply() then uses these attacker-controlled values as memcpy lengths when copying from kernel buffers that are only 6 and 4 bytes long, resulting in an out-of-bounds read of kernel heap and stack memory that is copied into the ARP reply sent back to the requester. An unauthenticated attacker on the adjacent network can use a single crafted ARP request to disclose up to roughly 250 bytes of each type of kernel memory, including kernel pointers. This is expected to be fixed in the 6.6 stable release when that is available.
Published: 2026-10-15
Score: 7.1 High
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

Vendor Solution

Update to DragonFly BSD 6.6 once released (the maintainers have confirmed the fix will be included), or apply commit 4bb22ffcf2e9fb44995fbfd9945194afc87fb182 from master, which rejects ARP packets whose ar_hln is not ETHER_ADDR_LEN in arpintr() and whose ar_pln is not sizeof(struct in_addr) in in_arpinput().

Tracking

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Advisories

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History

Thu, 15 Oct 2026 03:45:00 +0000

Type Values Removed Values Added
CPEs cpe:2.3:a:dragonflybsd:dragonflybsd:*:*:*:*:*:*:*:* cpe:2.3:o:dragonflybsd:dragonflybsd:*:*:*:*:*:*:*:*

Thu, 15 Oct 2026 03:30:00 +0000

Type Values Removed Values Added
Description In DragonFly BSD through 6.4.2 before 4bb22ff, the ARP input handlers arpintr() and in_arpinput() (sys/netinet/if_ether.c) do not validate the hardware address length (ar_hln) and protocol address length (ar_pln) fields of incoming ARP packets. in_arpreply() then uses these attacker-controlled values as memcpy lengths when copying from kernel buffers that are only 6 and 4 bytes long, resulting in an out-of-bounds read of kernel heap and stack memory that is copied into the ARP reply sent back to the requester. An unauthenticated attacker on the adjacent network can use a single crafted ARP request to disclose up to roughly 250 bytes of each type of kernel memory, including kernel pointers. This is expected to be fixed in the 6.6 stable release when that is available.
First Time appeared Dragonflybsd
Dragonflybsd dragonflybsd
Weaknesses CWE-130
CPEs cpe:2.3:a:dragonflybsd:dragonflybsd:*:*:*:*:*:*:*:*
Vendors & Products Dragonflybsd
Dragonflybsd dragonflybsd
References
Metrics cvssV4_0

{'score': 7.1, 'vector': 'CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N'}


Subscriptions

Dragonflybsd Dragonflybsd
cve-icon MITRE

Status: PUBLISHED

Assigner: mitre

Published:

Updated: 2026-10-15T03:26:47.830Z

Reserved: 2026-10-15T03:23:47.465Z

Link: CVE-2026-110912

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-10-15T04:18:23.010

Modified: 2026-10-15T04:18:23.010

Link: CVE-2026-110912

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses