CVE-2026-98812 Affecting linux-6.12 package, versions <6.12.113-1~deb12u1
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-DEBIAN12-LINUX612-21434893
- published23 Oct 2026
- disclosed18 Oct 2026
Introduced: 18 Oct 2026
NewCVE-2026-98812 (opens in a new tab)How to fix?
Upgrade Debian:12 linux-6.12 to version 6.12.113-1~deb12u1 or higher.
NVD Description
Note: Versions mentioned in the description apply only to the upstream linux-6.12 package and not the linux-6.12 package as distributed by Debian.
See How to fix? for Debian:12 relevant fixed versions and status.
In the Linux kernel, the following vulnerability has been resolved:
net/mctp: publish the mctp_dev only after it is initialised
mctp_add_dev() links the new mctp_dev into dev->mctp_ptr before mdev->dev is assigned, so a reader that picks the device up in that window dereferences a net_device pointer that is still NULL:
KASAN: null-ptr-deref in range [0x00000000000000b0-0x00000000000000b7] Call Trace: <TASK> ? __pfx_mctp_sendmsg (./include/linux/sockptr.h:49) ? __pfx_mctp_dst_output (net/mctp/route.c:41) ? selinux_socket_sendmsg (security/selinux/hooks.c:5278) ____sys_sendmsg (net/socket.c:775 (discriminator 1) net/socket.c:790 (discriminator 1) net/socket.c:2684 (discriminator 1)) ? __pfx_____sys_sendmsg (net/socket.c:1131) ? __pfx_copy_msghdr_from_user (net/socket.c:2590) ? update_cfs_rq_load_avg (kernel/sched/fair.c:5478) ___sys_sendmsg (net/socket.c:2738) ? __pfx____sys_sendmsg (net/socket.c:2625) ? perf_event_task_tick (./include/linux/rcupdate.h:838) ? sched_tick (kernel/sched/core.c:5818) ? clockevents_program_event (kernel/time/clockevents.c:372) ? fdget (./include/linux/rcupdate.h:873 fs/file.c:1100) __sys_sendmsg (net/socket.c:2770) ? __pfx___sys_sendmsg (net/socket.c:2751) do_syscall_64 (arch/x86/entry/syscall_64.c:63) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121) </TASK>
Fix by publishing only once the object is fully initialised: __mctp_dev_get() runs under rcu_read_lock() only and hands this object to readers as soon as mctp_ptr is assigned, so they must never observe mdev->dev == NULL.
References
- https://security-tracker.debian.org/tracker/CVE-2026-98812
- https://git.kernel.org/stable/c/63120572edde85bb2b70b0ed4d4817ed52247613
- https://git.kernel.org/stable/c/aadf655e8ea9a8ffa24bb8d69f504572e8d18181
- https://git.kernel.org/stable/c/af6e4f931afc2d670d133aa2bedc8b6e3753c618
- https://git.kernel.org/stable/c/f37f42e6e039a48c2dcf6c079b9f7fbc864ab7ef
- https://git.kernel.org/stable/c/288ef37e0c463192dbb6436e61cdc07ce666dcb9