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Vulnerability · Published Jun 26, 2026 · Assigned by Linux

CVE-2026-53309ocfs2/dlm: fix off-by-one in dlm_match_regions() region comparison

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 0.4% (higher than 34% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)9.8Critical
Exploit odds (30 days)0.4%top 65.7% 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: ocfs2/dlm: fix off-by-one in dlm_match_regions() region comparison The local-vs-remote region comparison loop uses '<=' instead of '<', causing it to read one entry past the valid range of qr_regions. The other loops in the same function correctly use '<'. Fix the loop condition to use '<' for consistency and correctness.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12linux6.1.176-1DEBIAN-CVE-2026-53309
Debian:13linux6.12.94-1DEBIAN-CVE-2026-53309
Debian:14linux7.0.10-1DEBIAN-CVE-2026-53309
Ubuntu:22.04:LTSlinux5.15.0-186.196UBUNTU-CVE-2026-53309
Ubuntu:24.04:LTSlinux6.8.0-136.136UBUNTU-CVE-2026-53309
Ubuntu:25.10linuxno fix listedUBUNTU-CVE-2026-53309
Ubuntu:26.04:LTSlinux7.0.0-28.28UBUNTU-CVE-2026-53309
Ubuntu:22.04:LTSlinux-allwinner-5.19no fix listedUBUNTU-CVE-2026-53309
Ubuntu:22.04:LTSlinux-aws5.15.0-1112.119UBUNTU-CVE-2026-53309
Ubuntu:24.04:LTSlinux-aws6.8.0-1061.64UBUNTU-CVE-2026-53309
Ubuntu:25.10linux-awsno fix listedUBUNTU-CVE-2026-53309
Ubuntu:26.04:LTSlinux-aws7.0.0-1009.9UBUNTU-CVE-2026-53309
Ubuntu:22.04:LTSlinux-aws-5.19no fix listedUBUNTU-CVE-2026-53309
Ubuntu:24.04:LTSlinux-aws-6.14no fix listedUBUNTU-CVE-2026-53309
Ubuntu:24.04:LTSlinux-aws-6.17no fix listedUBUNTU-CVE-2026-53309
Ubuntu:22.04:LTSlinux-aws-6.2no fix listedUBUNTU-CVE-2026-53309
Ubuntu:22.04:LTSlinux-aws-6.5no fix listedUBUNTU-CVE-2026-53309
Ubuntu:22.04:LTSlinux-aws-6.86.8.0-1061.64~22.04.1UBUNTU-CVE-2026-53309
Ubuntu:22.04:LTSlinux-azure5.15.0-1117.126UBUNTU-CVE-2026-53309
Ubuntu:24.04:LTSlinux-azure6.8.0-1063.71UBUNTU-CVE-2026-53309
Ubuntu:25.10linux-azureno fix listedUBUNTU-CVE-2026-53309
Ubuntu:26.04:LTSlinux-azure7.0.0-1010.10UBUNTU-CVE-2026-53309
Ubuntu:22.04:LTSlinux-azure-5.19no fix listedUBUNTU-CVE-2026-53309
Ubuntu:24.04:LTSlinux-azure-6.11no fix listedUBUNTU-CVE-2026-53309
Ubuntu:24.04:LTSlinux-azure-6.14no fix listedUBUNTU-CVE-2026-53309
Ubuntu:24.04:LTSlinux-azure-6.17no fix listedUBUNTU-CVE-2026-53309
Ubuntu:22.04:LTSlinux-azure-6.2no fix listedUBUNTU-CVE-2026-53309
Ubuntu:22.04:LTSlinux-azure-6.5no fix listedUBUNTU-CVE-2026-53309
Ubuntu:22.04:LTSlinux-azure-6.86.8.0-1063.71~22.04.1UBUNTU-CVE-2026-53309
Ubuntu:24.04:LTSlinux-azure-7.07.0.0-1014.14~24.04.1UBUNTU-CVE-2026-53309
Ubuntu:22.04:LTSlinux-azure-fde5.15.0-1117.126UBUNTU-CVE-2026-53309
Ubuntu:24.04:LTSlinux-azure-fde6.8.0-1062.69UBUNTU-CVE-2026-53309
Ubuntu:25.10linux-azure-fdeno fix listedUBUNTU-CVE-2026-53309
Ubuntu:26.04:LTSlinux-azure-fde7.0.0-1009.9UBUNTU-CVE-2026-53309
Ubuntu:22.04:LTSlinux-azure-fde-5.19no fix listedUBUNTU-CVE-2026-53309
Ubuntu:24.04:LTSlinux-azure-fde-6.14no fix listedUBUNTU-CVE-2026-53309
Ubuntu:22.04:LTSlinux-azure-fde-6.2no fix listedUBUNTU-CVE-2026-53309
Ubuntu:22.04:LTSlinux-azure-fde-6.86.8.0-1062.69~22.04.1UBUNTU-CVE-2026-53309
Ubuntu:24.04:LTSlinux-azure-fde-7.07.0.0-1013.13~24.04.1UBUNTU-CVE-2026-53309
Ubuntu:24.04:LTSlinux-azure-nvidiano fix listedUBUNTU-CVE-2026-53309
Ubuntu:24.04:LTSlinux-azure-nvidia-6.14no fix listedUBUNTU-CVE-2026-53309
Ubuntu:22.04:LTSlinux-gcp5.15.0-1112.122UBUNTU-CVE-2026-53309
Ubuntu:24.04:LTSlinux-gcp6.8.0-1064.72UBUNTU-CVE-2026-53309
Ubuntu:25.10linux-gcpno fix listedUBUNTU-CVE-2026-53309
Ubuntu:26.04:LTSlinux-gcp7.0.0-1008.8UBUNTU-CVE-2026-53309
Ubuntu:22.04:LTSlinux-gcp-5.19no fix listedUBUNTU-CVE-2026-53309
Ubuntu:24.04:LTSlinux-gcp-6.11no fix listedUBUNTU-CVE-2026-53309
Ubuntu:24.04:LTSlinux-gcp-6.14no fix listedUBUNTU-CVE-2026-53309
Ubuntu:24.04:LTSlinux-gcp-6.17no fix listedUBUNTU-CVE-2026-53309
Ubuntu:22.04:LTSlinux-gcp-6.2no fix listedUBUNTU-CVE-2026-53309
Ubuntu:22.04:LTSlinux-gcp-6.5no fix listedUBUNTU-CVE-2026-53309
Ubuntu:22.04:LTSlinux-gcp-6.86.8.0-1064.72~22.04.1UBUNTU-CVE-2026-53309
Ubuntu:24.04:LTSlinux-gcp-7.07.0.0-1011.11~24.04.1UBUNTU-CVE-2026-53309
Ubuntu:22.04:LTSlinux-gke5.15.0-1108.114UBUNTU-CVE-2026-53309
Ubuntu:24.04:LTSlinux-gke6.8.0-1059.67UBUNTU-CVE-2026-53309
Ubuntu:26.04:LTSlinux-gke7.0.0-1003.4UBUNTU-CVE-2026-53309
Ubuntu:22.04:LTSlinux-gkeop5.15.0-1095.103UBUNTU-CVE-2026-53309
Ubuntu:24.04:LTSlinux-gkeop6.8.0-1046.50UBUNTU-CVE-2026-53309
Ubuntu:22.04:LTSlinux-hwe-5.19no fix listedUBUNTU-CVE-2026-53309
Ubuntu:24.04:LTSlinux-hwe-6.11no fix listedUBUNTU-CVE-2026-53309
Ubuntu:24.04:LTSlinux-hwe-6.14no fix listedUBUNTU-CVE-2026-53309
Ubuntu:24.04:LTSlinux-hwe-6.17no fix listedUBUNTU-CVE-2026-53309
Ubuntu:22.04:LTSlinux-hwe-6.2no fix listedUBUNTU-CVE-2026-53309
Ubuntu:22.04:LTSlinux-hwe-6.5no fix listedUBUNTU-CVE-2026-53309
Ubuntu:22.04:LTSlinux-hwe-6.86.8.0-136.136~22.04.1UBUNTU-CVE-2026-53309
Ubuntu:24.04:LTSlinux-hwe-7.07.0.0-28.28~24.04.1UBUNTU-CVE-2026-53309
Ubuntu:22.04:LTSlinux-ibm5.15.0-1106.110UBUNTU-CVE-2026-53309
Ubuntu:24.04:LTSlinux-ibm6.8.0-1061.62UBUNTU-CVE-2026-53309
Ubuntu:26.04:LTSlinux-ibm7.0.0-1010.10UBUNTU-CVE-2026-53309
Ubuntu:22.04:LTSlinux-ibm-6.86.8.0-1061.62~22.04.1UBUNTU-CVE-2026-53309
Ubuntu:22.04:LTSlinux-intel-iot-realtimeno fix listedUBUNTU-CVE-2026-53309
Ubuntu:22.04:LTSlinux-intel-iotg5.15.0-1107.113UBUNTU-CVE-2026-53309
Ubuntu:22.04:LTSlinux-kvm5.15.0-1104.109UBUNTU-CVE-2026-53309
Ubuntu:22.04:LTSlinux-lowlatency5.15.0-184.194UBUNTU-CVE-2026-53309
Ubuntu:24.04:LTSlinux-lowlatency6.8.0-136.136.2UBUNTU-CVE-2026-53309
Ubuntu:22.04:LTSlinux-lowlatency-hwe-5.19no fix listedUBUNTU-CVE-2026-53309
Ubuntu:24.04:LTSlinux-lowlatency-hwe-6.11no fix listedUBUNTU-CVE-2026-53309
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.2no fix listedUBUNTU-CVE-2026-53309
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.5no fix listedUBUNTU-CVE-2026-53309
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.86.8.0-136.136.2~22.04.1UBUNTU-CVE-2026-53309
Ubuntu:22.04:LTSlinux-nvidia5.15.0-1107.108UBUNTU-CVE-2026-53309
Ubuntu:24.04:LTSlinux-nvidia6.8.0-1059.62UBUNTU-CVE-2026-53309
Ubuntu:26.04:LTSlinux-nvidia7.0.0-1016.16UBUNTU-CVE-2026-53309
Ubuntu:24.04:LTSlinux-nvidia-6.11no fix listedUBUNTU-CVE-2026-53309
Ubuntu:24.04:LTSlinux-nvidia-6.176.17.0-1032.32UBUNTU-CVE-2026-53309
Ubuntu:24.04:LTSlinux-nvidia-6.176.17.0-1032.32USN-8748-1
Ubuntu:22.04:LTSlinux-nvidia-6.2no fix listedUBUNTU-CVE-2026-53309
Ubuntu:22.04:LTSlinux-nvidia-6.5no fix listedUBUNTU-CVE-2026-53309
Ubuntu:22.04:LTSlinux-nvidia-6.86.8.0-1059.62~22.04.1UBUNTU-CVE-2026-53309
Ubuntu:24.04:LTSlinux-nvidia-7.07.0.0-1016.16~24.04.1UBUNTU-CVE-2026-53309
Ubuntu:26.04:LTSlinux-nvidia-bos7.0.0-2016.16UBUNTU-CVE-2026-53309
Ubuntu:24.04:LTSlinux-nvidia-lowlatency6.8.0-1059.62.1UBUNTU-CVE-2026-53309
Ubuntu:22.04:LTSlinux-nvidia-tegra5.15.0-1064.66UBUNTU-CVE-2026-53309
Ubuntu:24.04:LTSlinux-nvidia-tegra6.8.0-1030.31UBUNTU-CVE-2026-53309
Ubuntu:22.04:LTSlinux-nvidia-tegra-igx5.15.0-1053.53UBUNTU-CVE-2026-53309
Ubuntu:22.04:LTSlinux-oem-5.17no fix listedUBUNTU-CVE-2026-53309
Ubuntu:22.04:LTSlinux-oem-6.0no fix listedUBUNTU-CVE-2026-53309
Ubuntu:22.04:LTSlinux-oem-6.1no fix listedUBUNTU-CVE-2026-53309
Ubuntu:24.04:LTSlinux-oem-6.11no fix listedUBUNTU-CVE-2026-53309
Ubuntu:24.04:LTSlinux-oem-6.14no fix listedUBUNTU-CVE-2026-53309
Ubuntu:24.04:LTSlinux-oem-6.176.17.0-1033.33USN-8911-1
Ubuntu:24.04:LTSlinux-oem-6.176.17.0-1033.33UBUNTU-CVE-2026-53309
Ubuntu:22.04:LTSlinux-oem-6.5no fix listedUBUNTU-CVE-2026-53309
Ubuntu:24.04:LTSlinux-oem-6.8no fix listedUBUNTU-CVE-2026-53309
Ubuntu:26.04:LTSlinux-oem-7.07.0.0-1009.9UBUNTU-CVE-2026-53309
Ubuntu:22.04:LTSlinux-oracle5.15.0-1109.115UBUNTU-CVE-2026-53309
Ubuntu:24.04:LTSlinux-oracle6.8.0-1058.61UBUNTU-CVE-2026-53309
Ubuntu:25.10linux-oracleno fix listedUBUNTU-CVE-2026-53309
Ubuntu:26.04:LTSlinux-oracle7.0.0-1008.8UBUNTU-CVE-2026-53309
Ubuntu:24.04:LTSlinux-oracle-6.14no fix listedUBUNTU-CVE-2026-53309
Ubuntu:24.04:LTSlinux-oracle-6.17no fix listedUBUNTU-CVE-2026-53309
Ubuntu:22.04:LTSlinux-oracle-6.5no fix listedUBUNTU-CVE-2026-53309
Ubuntu:22.04:LTSlinux-oracle-6.86.8.0-1058.61~22.04.1UBUNTU-CVE-2026-53309
Ubuntu:24.04:LTSlinux-oracle-7.07.0.0-1011.11~24.04.1UBUNTU-CVE-2026-53309
Ubuntu:22.04:LTSlinux-raspi5.15.0-1106.109UBUNTU-CVE-2026-53309
Ubuntu:24.04:LTSlinux-raspi6.8.0-1061.65UBUNTU-CVE-2026-53309
Ubuntu:25.10linux-raspino fix listedUBUNTU-CVE-2026-53309
Ubuntu:26.04:LTSlinux-raspi7.0.0-1015.15UBUNTU-CVE-2026-53309
Ubuntu:24.04:LTSlinux-raspi-realtimeno fix listedUBUNTU-CVE-2026-53309
Ubuntu:22.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-53309
Ubuntu:24.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-53309
Ubuntu:25.10linux-realtimeno fix listedUBUNTU-CVE-2026-53309
Ubuntu:26.04:LTSlinux-realtime7.0.0-28.28.1UBUNTU-CVE-2026-53309
Ubuntu:22.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2026-53309
Ubuntu:24.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2026-53309
Ubuntu:25.10linux-riscvno fix listedUBUNTU-CVE-2026-53309
Ubuntu:26.04:LTSlinux-riscv7.0.0-28.28.1UBUNTU-CVE-2026-53309
Ubuntu:22.04:LTSlinux-riscv-5.19no fix listedUBUNTU-CVE-2026-53309
Ubuntu:24.04:LTSlinux-riscv-6.14no fix listedUBUNTU-CVE-2026-53309
Ubuntu:24.04:LTSlinux-riscv-6.17no fix listedUBUNTU-CVE-2026-53309
Ubuntu:22.04:LTSlinux-riscv-6.5no fix listedUBUNTU-CVE-2026-53309
Ubuntu:22.04:LTSlinux-riscv-6.86.8.0-136.136~22.04.3UBUNTU-CVE-2026-53309
Ubuntu:24.04:LTSlinux-riscv-7.07.0.0-28.28.1~24.04.3UBUNTU-CVE-2026-53309
Ubuntu:22.04:LTSlinux-starfive-5.19no fix listedUBUNTU-CVE-2026-53309
Ubuntu:22.04:LTSlinux-starfive-6.2no fix listedUBUNTU-CVE-2026-53309
Ubuntu:22.04:LTSlinux-starfive-6.5no fix listedUBUNTU-CVE-2026-53309
Ubuntu:24.04:LTSlinux-vmware6.8.0-1008.8UBUNTU-CVE-2026-53309
Ubuntu:24.04:LTSlinux-xilinx6.8.0-1033.34UBUNTU-CVE-2026-53309
Ubuntu:22.04:LTSlinux-xilinx-zynqmp5.15.0-1075.79UBUNTU-CVE-2026-53309

Affected products (as reported)

VendorProductVersions
Linux Linux ea2034416b54700e30371f2ad6517cbb94674083 – before 760ab35040aca8399021fdb9ff1db1089feb7194ea2034416b54700e30371f2ad6517cbb94674083 – before c60a2710b73838d250cda57344c049b89abc5d52ea2034416b54700e30371f2ad6517cbb94674083 – before 2a0673836f019e7c032acbf48d022d5ccf02a845ea2034416b54700e30371f2ad6517cbb94674083 – before 819d8ebad3200a53de99bd7e297bc428e41ced54ea2034416b54700e30371f2ad6517cbb94674083 – before d5403ae28085761d58b555645bc7d5feadb10073ea2034416b54700e30371f2ad6517cbb94674083 – before 1fb7f356547d9688822315cd2b205ff0bd5429b4ea2034416b54700e30371f2ad6517cbb94674083 – before 426cd8eedac89b86148d4478990eeef16e8a2520ea2034416b54700e30371f2ad6517cbb94674083 – before 01b61e8dda9b0fdb0d4cda43de25f4e390554d7b
Linux Linux 2.6.37

References