CVE-2026-98238 net: wwan: t7xx: validate the netif index in t7xx_ccmni_recv_skb()
A missing bounds check in the Linux kernel t7xx WWAN driver allows out-of-bounds reads and potential code execution via crafted network packets.
- 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-2026-98238?
CVE-2026-98238 is a memory corruption vulnerability in Linux, published on 6 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:
net: wwan: t7xx: validate the netif index in t7xx_ccmni_recv_skb()
The netif index carried in the DPMAIF PIT header is five bits wide, but ccmni_inst[] only has room for NIC_DEV_MAX (21) entries. t7xx_ccmni_recv_skb() indexes the array without a bounds check, so indexes 21 to 31 read past it. The out-of-bounds value lands in the callback table that follows the array, which is never NULL, so the existing !ccmni check does not catch it and the driver dereferences whatever sits there as a struct t7xx_ccmni.
Drop the skb when the index is out of range.
Verified in a QEMU guest with a fault injector setting the netif index to 25: the unpatched driver reads a value past ccmni_inst[], which lands in the callback table, and dereferences it far enough to queue the skb. With this check the packet is dropped. Well-formed traffic on index 0 is unaffected.
Changes in v2: none.
Which versions are affected by CVE-2026-98238?
How do I fix CVE-2026-98238?
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-2026-98238 being exploited?
There is no known exploitation of CVE-2026-98238 in the wild and no public exploit code.
Sources
Also known as AZL-106206, BELL-CVE-2026-98238, DEBIAN-CVE-2026-98238, GHSA-wwj9-jxr5-39jp, UBUNTU-CVE-2026-98238.