CVE-2026-31675 net/sched: sch_netem: fix out-of-bounds access in packet corruption
A local attacker can trigger an out-of-bounds memory access in the Linux kernel's netem scheduler by sending specific non-linear packets, potentially leading to code execution or system crash.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-31675?
CVE-2026-31675 is a high-severity memory corruption vulnerability in Linux kernel, published on 25 Apr 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:
net/sched: sch_netem: fix out-of-bounds access in packet corruption
In netem_enqueue(), the packet corruption logic uses get_random_u32_below(skb_headlen(skb)) to select an index for modifying skb->data. When an AF_PACKET TX_RING sends fully non-linear packets over an IPIP tunnel, skb_headlen(skb) evaluates to 0.
Passing 0 to get_random_u32_below() takes the variable-ceil slow path which returns an unconstrained 32-bit random integer. Using this unconstrained value as an offset into skb->data results in an out-of-bounds memory access.
Fix this by verifying skb_headlen(skb) is non-zero before attempting to corrupt the linear data area. Fully non-linear packets will silently bypass the corruption logic.
Which versions are affected by CVE-2026-31675?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-31675?
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-2026-31675 being exploited?
There is no known exploitation of CVE-2026-31675 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-84204, BELL-CVE-2026-31675, DEBIAN-CVE-2026-31675, GHSA-2gh3-wm75-4q8m, ROOT-OS-DEBIAN-11-CVE-2026-31675, ROOT-OS-DEBIAN-12-CVE-2026-31675 and 3 more.