CVE-2026-89990 Affecting linux-6.12 package, versions <6.12.111-1~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-LINUX612-20506673
- published5 Oct 2026
- disclosed16 Sept 2026
Introduced: 16 Sep 2026
NewCVE-2026-89990 (opens in a new tab)How to fix?
Upgrade Debian:12 linux-6.12 to version 6.12.111-1~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:
ceph: lock mutex in ceph_mds_check_access()
MDS session OPEN handling replaces mdsc->s_cap_auths under mdsc->mutex, freeing the previous array and its strings.
ceph_mds_check_access() traverses this array without holding the mutex. A concurrent session reopen can therefore free the array while it is being inspected, resulting in a use-after-free like this:
Unable to handle kernel paging request at virtual address 003aaad64b2c8bb9 [...] Internal error: Oops: 0000000096000004 [#1] SMP Modules linked in: CPU: 56 UID: 2953037534 PID: 1253231 Comm: php-cgi8.4 Not tainted 6.18.45-i2-ampere #1146 NONE [..] pc : ceph_mds_check_access+0xd4/0x550 lr : ceph_mds_check_access+0xc8/0x550 [...] Call trace: ceph_mds_check_access+0xd4/0x550 (P) ceph_atomic_open+0x138/0xbe8 path_openat+0xa24/0xfa8 do_filp_open+0x94/0x158 do_sys_openat2+0x88/0xf8
References
- https://security-tracker.debian.org/tracker/CVE-2026-89990
- https://git.kernel.org/stable/c/729c1ff670ece6f3d4b1738365a0b2f90d487523
- https://git.kernel.org/stable/c/a61c6ae1dae2611082b831b4aaa780878099c012
- https://git.kernel.org/stable/c/ca5bfea2045ef2eb3305cf2a9d8da549b76c37d3
- https://git.kernel.org/stable/c/df1a97d5313fccadb08390306d49b194fb027392