CVE-2026-98419 drop_monitor: fix out-of-bounds write in reset_per_cpu_data()
A local attacker can trigger an out-of-bounds write in the Linux kernel drop_monitor module, potentially leading to memory corruption and privilege escalation.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-98419?
CVE-2026-98419 is a high-severity memory corruption vulnerability in Linux, published on 14 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
drop_monitor: fix out-of-bounds write in reset_per_cpu_data()
In reset_per_cpu_data(), al is computed as:
al = sizeof(struct net_dm_alert_msg); al += dm_hit_limit * sizeof(struct net_dm_drop_point); al += sizeof(struct nlattr);
skb = genlmsg_new(al, GFP_KERNEL); ... nla = nla_reserve(skb, NLA_UNSPEC, sizeof(struct net_dm_alert_msg)); ... msg = nla_data(nla); memset(msg, 0, al);
Because al includes sizeof(struct nlattr) (the 4-byte attribute header), genlmsg_new() allocates al bytes of tailroom starting at nla. However, msg points to nla_data(nla), which is located sizeof(struct nlattr) bytes past nla. Calling memset(msg, 0, al) therefore writes al bytes starting from msg, exceeding the allocated buffer by sizeof(struct nlattr) (4 bytes) and corrupting skb_shared_info.
Fix this by letting al represent only the payload length, allocating the skb with genlmsg_new(nla_total_size(al), GFP_KERNEL), and zeroing al bytes from msg.
Which versions are affected by CVE-2026-98419?
How do I fix CVE-2026-98419?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-98419 being exploited?
There is no known exploitation of CVE-2026-98419 in the wild and no public exploit code.
Sources
Also known as AZL-108162, BELL-CVE-2026-98419, DEBIAN-CVE-2026-98419, GHSA-6j59-9ph5-7p77, UBUNTU-CVE-2026-98419.