CVE-2026-110912: DragonFly BSD DragonFly BSD vulnerability
In DragonFly BSD through 6.4.2 before 4bb22ff, the ARP input handlers arpintr() and inarpinput() (sys/netinet/ifether.c) do not validate the hardware address length (arhln) and protocol address length (arpln) fields of incoming ARP packets. inarpreply() 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.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
DragonFly BSDto a version that resolves this vulnerability.Fixed in 6.6Patch 4bb22ffcf2e9fb44995fbfd9945194afc87fb182
Event History
Frequently Asked Questions
Which systems are exposed?
DragonFly BSD systems through 6.4.2 are affected unless they include commit 4bb22ffcf2e9fb44995fbfd9945194afc87fb182. The issue is expected to be fixed in the 6.6 stable release when available.
What access does an attacker need?
An attacker must be on an adjacent network and able to send a crafted ARP request to the target. No authentication is required.
What could be disclosed?
A single crafted request can cause an ARP reply to expose roughly 250 bytes each of kernel heap and stack memory. The disclosed data may include kernel pointers.