CVE-2026-68287 drop_monitor: fix size calculations for 64-bit attributes
An integer overflow in Linux kernel drop_monitor size calculations can cause a kernel panic, leading to denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-68287?
CVE-2026-68287 is a high-severity vulnerability in Linux, published on 10 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
drop_monitor: fix size calculations for 64-bit attributes
net_dm_packet_report_fill() and net_dm_hw_packet_report_fill() use nla_put_u64_64bit() to append 64-bit attributes (NET_DM_ATTR_PC and NET_DM_ATTR_TIMESTAMP).
On 32-bit architectures without CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS, nla_put_u64_64bit() may append a 4-byte NET_DM_ATTR_PAD attribute for 64-bit alignment.
However, net_dm_packet_report_size() and net_dm_hw_packet_report_size() used nla_total_size(sizeof(u64)) instead of nla_total_size_64bit(sizeof(u64)), budgeting 12 bytes instead of up to 16 bytes.
This under-estimation of SKB size can lead to an skb_over_panic() when __nla_reserve() or skb_put() is subsequently called.
Fix this by using nla_total_size_64bit(sizeof(u64)) in both size calculations.
Weakness: CWE-131
Which versions are affected by CVE-2026-68287?
How do I fix CVE-2026-68287?
Apply the vendor's patch.
Is CVE-2026-68287 being exploited?
There is no known exploitation of CVE-2026-68287 in the wild and no public exploit code.
Sources
Also known as AZL-94968, BELL-CVE-2026-68287, DEBIAN-CVE-2026-68287, GHSA-mc29-r954-2m26, UBUNTU-CVE-2026-68287.