Vulnerability · Published Sep 16, 2026 · Assigned by Linux

CVE-2026-89990ceph: lock mutex in ceph_mds_check_access()

Critical 9.8

In plain English

A critical-severity security flaw in Linux from Linux. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 49% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)9.8Critical
Exploit odds (30 days)0.6%top 50.7% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known

Official description

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

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:13linux6.12.111-1DEBIAN-CVE-2026-89990
Debian:14linux7.2.6-1DEBIAN-CVE-2026-89990
Debian:12linux-6.126.12.111-1~deb12u1DEBIAN-CVE-2026-89990
Ubuntu:26.04:LTSlinux7.0.0-42.42UBUNTU-CVE-2026-89990
Ubuntu:22.04:LTSlinux-allwinner-5.19no fix listedUBUNTU-CVE-2026-89990
Ubuntu:26.04:LTSlinux-aws7.0.0-1016.17UBUNTU-CVE-2026-89990
Ubuntu:22.04:LTSlinux-aws-5.19no fix listedUBUNTU-CVE-2026-89990
Ubuntu:24.04:LTSlinux-aws-6.14no fix listedUBUNTU-CVE-2026-89990
Ubuntu:24.04:LTSlinux-aws-6.17no fix listedUBUNTU-CVE-2026-89990
Ubuntu:22.04:LTSlinux-aws-6.2no fix listedUBUNTU-CVE-2026-89990
Ubuntu:22.04:LTSlinux-aws-6.5no fix listedUBUNTU-CVE-2026-89990
Ubuntu:24.04:LTSlinux-aws-7.0no fix listedUBUNTU-CVE-2026-89990
Ubuntu:26.04:LTSlinux-azureno fix listedUBUNTU-CVE-2026-89990
Ubuntu:22.04:LTSlinux-azure-5.19no fix listedUBUNTU-CVE-2026-89990
Ubuntu:24.04:LTSlinux-azure-6.11no fix listedUBUNTU-CVE-2026-89990
Ubuntu:24.04:LTSlinux-azure-6.14no fix listedUBUNTU-CVE-2026-89990
Ubuntu:24.04:LTSlinux-azure-6.17no fix listedUBUNTU-CVE-2026-89990
Ubuntu:22.04:LTSlinux-azure-6.2no fix listedUBUNTU-CVE-2026-89990
Ubuntu:22.04:LTSlinux-azure-6.5no fix listedUBUNTU-CVE-2026-89990
Ubuntu:24.04:LTSlinux-azure-7.0no fix listedUBUNTU-CVE-2026-89990
Ubuntu:26.04:LTSlinux-azure-fdeno fix listedUBUNTU-CVE-2026-89990
Ubuntu:22.04:LTSlinux-azure-fde-5.19no fix listedUBUNTU-CVE-2026-89990
Ubuntu:24.04:LTSlinux-azure-fde-6.14no fix listedUBUNTU-CVE-2026-89990
Ubuntu:24.04:LTSlinux-azure-fde-6.17no fix listedUBUNTU-CVE-2026-89990
Ubuntu:22.04:LTSlinux-azure-fde-6.2no fix listedUBUNTU-CVE-2026-89990
Ubuntu:24.04:LTSlinux-azure-fde-7.0no fix listedUBUNTU-CVE-2026-89990
Ubuntu:24.04:LTSlinux-azure-nvidia-6.14no fix listedUBUNTU-CVE-2026-89990
Ubuntu:26.04:LTSlinux-gcp7.0.0-1016.18UBUNTU-CVE-2026-89990
Ubuntu:22.04:LTSlinux-gcp-5.19no fix listedUBUNTU-CVE-2026-89990
Ubuntu:24.04:LTSlinux-gcp-6.11no fix listedUBUNTU-CVE-2026-89990
Ubuntu:24.04:LTSlinux-gcp-6.14no fix listedUBUNTU-CVE-2026-89990
Ubuntu:24.04:LTSlinux-gcp-6.17no fix listedUBUNTU-CVE-2026-89990
Ubuntu:22.04:LTSlinux-gcp-6.2no fix listedUBUNTU-CVE-2026-89990
Ubuntu:22.04:LTSlinux-gcp-6.5no fix listedUBUNTU-CVE-2026-89990
Ubuntu:24.04:LTSlinux-gcp-7.0no fix listedUBUNTU-CVE-2026-89990
Ubuntu:26.04:LTSlinux-gkeno fix listedUBUNTU-CVE-2026-89990
Ubuntu:22.04:LTSlinux-hwe-5.19no fix listedUBUNTU-CVE-2026-89990
Ubuntu:24.04:LTSlinux-hwe-6.11no fix listedUBUNTU-CVE-2026-89990
Ubuntu:24.04:LTSlinux-hwe-6.14no fix listedUBUNTU-CVE-2026-89990
Ubuntu:24.04:LTSlinux-hwe-6.17no fix listedUBUNTU-CVE-2026-89990
Ubuntu:22.04:LTSlinux-hwe-6.2no fix listedUBUNTU-CVE-2026-89990
Ubuntu:22.04:LTSlinux-hwe-6.5no fix listedUBUNTU-CVE-2026-89990
Ubuntu:24.04:LTSlinux-hwe-7.07.0.0-42.42~24.04.1UBUNTU-CVE-2026-89990
Ubuntu:26.04:LTSlinux-ibm7.0.0-1017.17UBUNTU-CVE-2026-89990
Ubuntu:22.04:LTSlinux-intel-iot-realtimeno fix listedUBUNTU-CVE-2026-89990
Ubuntu:22.04:LTSlinux-lowlatency-hwe-5.19no fix listedUBUNTU-CVE-2026-89990
Ubuntu:24.04:LTSlinux-lowlatency-hwe-6.11no fix listedUBUNTU-CVE-2026-89990
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.2no fix listedUBUNTU-CVE-2026-89990
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.5no fix listedUBUNTU-CVE-2026-89990
Ubuntu:26.04:LTSlinux-nvidiano fix listedUBUNTU-CVE-2026-89990
Ubuntu:24.04:LTSlinux-nvidia-6.11no fix listedUBUNTU-CVE-2026-89990
Ubuntu:24.04:LTSlinux-nvidia-6.17no fix listedUBUNTU-CVE-2026-89990
Ubuntu:22.04:LTSlinux-nvidia-6.2no fix listedUBUNTU-CVE-2026-89990
Ubuntu:22.04:LTSlinux-nvidia-6.5no fix listedUBUNTU-CVE-2026-89990
Ubuntu:24.04:LTSlinux-nvidia-7.0no fix listedUBUNTU-CVE-2026-89990
Ubuntu:26.04:LTSlinux-nvidia-bosno fix listedUBUNTU-CVE-2026-89990
Ubuntu:22.04:LTSlinux-oem-5.17no fix listedUBUNTU-CVE-2026-89990
Ubuntu:22.04:LTSlinux-oem-6.0no fix listedUBUNTU-CVE-2026-89990
Ubuntu:22.04:LTSlinux-oem-6.1no fix listedUBUNTU-CVE-2026-89990
Ubuntu:24.04:LTSlinux-oem-6.11no fix listedUBUNTU-CVE-2026-89990
Ubuntu:24.04:LTSlinux-oem-6.14no fix listedUBUNTU-CVE-2026-89990
Ubuntu:24.04:LTSlinux-oem-6.17no fix listedUBUNTU-CVE-2026-89990
Ubuntu:22.04:LTSlinux-oem-6.5no fix listedUBUNTU-CVE-2026-89990
Ubuntu:24.04:LTSlinux-oem-6.8no fix listedUBUNTU-CVE-2026-89990
Ubuntu:26.04:LTSlinux-oem-7.07.0.0-1017.17UBUNTU-CVE-2026-89990
Ubuntu:26.04:LTSlinux-oracle7.0.0-1015.16UBUNTU-CVE-2026-89990
Ubuntu:24.04:LTSlinux-oracle-6.14no fix listedUBUNTU-CVE-2026-89990
Ubuntu:24.04:LTSlinux-oracle-6.17no fix listedUBUNTU-CVE-2026-89990
Ubuntu:22.04:LTSlinux-oracle-6.5no fix listedUBUNTU-CVE-2026-89990
Ubuntu:24.04:LTSlinux-oracle-7.0no fix listedUBUNTU-CVE-2026-89990
Ubuntu:26.04:LTSlinux-raspino fix listedUBUNTU-CVE-2026-89990
Ubuntu:24.04:LTSlinux-raspi-realtimeno fix listedUBUNTU-CVE-2026-89990
Ubuntu:22.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-89990
Ubuntu:24.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-89990
Ubuntu:26.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-89990
Ubuntu:22.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2026-89990
Ubuntu:24.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2026-89990
Ubuntu:26.04:LTSlinux-riscv7.0.0-42.42.1UBUNTU-CVE-2026-89990
Ubuntu:22.04:LTSlinux-riscv-5.19no fix listedUBUNTU-CVE-2026-89990
Ubuntu:24.04:LTSlinux-riscv-6.14no fix listedUBUNTU-CVE-2026-89990
Ubuntu:24.04:LTSlinux-riscv-6.17no fix listedUBUNTU-CVE-2026-89990
Ubuntu:22.04:LTSlinux-riscv-6.5no fix listedUBUNTU-CVE-2026-89990
Ubuntu:24.04:LTSlinux-riscv-7.07.0.0-42.42.1~24.04.1UBUNTU-CVE-2026-89990
Ubuntu:22.04:LTSlinux-starfive-5.19no fix listedUBUNTU-CVE-2026-89990
Ubuntu:22.04:LTSlinux-starfive-6.2no fix listedUBUNTU-CVE-2026-89990
Ubuntu:22.04:LTSlinux-starfive-6.5no fix listedUBUNTU-CVE-2026-89990

Affected products (as reported)

VendorProductVersions
Linux Linux 596afb0b8933ba6ed7227adcc538db26feb25c74 – before 729c1ff670ece6f3d4b1738365a0b2f90d487523596afb0b8933ba6ed7227adcc538db26feb25c74 – before ca5bfea2045ef2eb3305cf2a9d8da549b76c37d3596afb0b8933ba6ed7227adcc538db26feb25c74 – before df1a97d5313fccadb08390306d49b194fb027392596afb0b8933ba6ed7227adcc538db26feb25c74 – before a61c6ae1dae2611082b831b4aaa780878099c012
Linux Linux 6.10

References