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Vulnerability · Published Jul 19, 2026 · Assigned by Linux

CVE-2026-63802blk-cgroup: fix UAF in __blkcg_rstat_flush()

High 7.8

In plain English

A high-severity race condition 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 0.1% (higher than 1% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.8High
Exploit odds (30 days)0.1%top 99.1% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

In the Linux kernel, the following vulnerability has been resolved: blk-cgroup: fix UAF in __blkcg_rstat_flush() When multiple blkgs in the same blkcg are released concurrently, a use-after-free can occur. The race happens when one blkg's __blkcg_rstat_flush() removes another blkg's iostat entries via llist_del_all(). The second blkg sees an empty list and proceeds to free itself while the first is still iterating over its entries. Move the flush from __blkg_release() (RCU callback) to blkg_release() (before call_rcu). This ensures the RCU grace period waits for any concurrent flush's rcu_read_lock() section to complete before freeing.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
AlmaLinux:8bpftool4.18.0-553.163.1.el8_10ALSA-2026:67468
AlmaLinux:8kernel4.18.0-553.163.1.el8_10ALSA-2026:67468
AlmaLinux:9kernel5.14.0-687.51.1.el9_8ALSA-2026:71232
AlmaLinux:9kernel-64k5.14.0-687.51.1.el9_8ALSA-2026:71232
AlmaLinux:9kernel-64k-core5.14.0-687.51.1.el9_8ALSA-2026:71232
AlmaLinux:9kernel-64k-debug5.14.0-687.51.1.el9_8ALSA-2026:71232
AlmaLinux:9kernel-64k-debug-core5.14.0-687.51.1.el9_8ALSA-2026:71232
AlmaLinux:10kernel-64k-debug-devel6.12.0-211.59.1.el10_2ALSA-2026:71233
AlmaLinux:10kernel-64k-debug-devel-matched6.12.0-211.59.1.el10_2ALSA-2026:71233
AlmaLinux:9kernel-64k-debug-modules5.14.0-687.51.1.el9_8ALSA-2026:71232
AlmaLinux:9kernel-64k-debug-modules-core5.14.0-687.51.1.el9_8ALSA-2026:71232
AlmaLinux:9kernel-64k-debug-modules-extra5.14.0-687.51.1.el9_8ALSA-2026:71232
AlmaLinux:10kernel-64k-devel6.12.0-211.59.1.el10_2ALSA-2026:71233
AlmaLinux:10kernel-64k-devel-matched6.12.0-211.59.1.el10_2ALSA-2026:71233
AlmaLinux:9kernel-64k-modules5.14.0-687.51.1.el9_8ALSA-2026:71232
AlmaLinux:9kernel-64k-modules-core5.14.0-687.51.1.el9_8ALSA-2026:71232
AlmaLinux:9kernel-64k-modules-extra5.14.0-687.51.1.el9_8ALSA-2026:71232
AlmaLinux:8kernel-abi-stablelists4.18.0-553.163.1.el8_10ALSA-2026:67468
AlmaLinux:9kernel-abi-stablelists5.14.0-687.51.1.el9_8ALSA-2026:71232
AlmaLinux:8kernel-core4.18.0-553.163.1.el8_10ALSA-2026:67468
AlmaLinux:9kernel-core5.14.0-687.51.1.el9_8ALSA-2026:71232
AlmaLinux:8kernel-cross-headers4.18.0-553.163.1.el8_10ALSA-2026:67468
AlmaLinux:8kernel-debug4.18.0-553.163.1.el8_10ALSA-2026:67468
AlmaLinux:9kernel-debug5.14.0-687.51.1.el9_8ALSA-2026:71232
AlmaLinux:8kernel-debug-core4.18.0-553.163.1.el8_10ALSA-2026:67468
AlmaLinux:9kernel-debug-core5.14.0-687.51.1.el9_8ALSA-2026:71232
AlmaLinux:10kernel-debug-devel6.12.0-211.59.1.el10_2ALSA-2026:71233
AlmaLinux:8kernel-debug-devel4.18.0-553.163.1.el8_10ALSA-2026:67468
AlmaLinux:10kernel-debug-devel-matched6.12.0-211.59.1.el10_2ALSA-2026:71233
AlmaLinux:8kernel-debug-modules4.18.0-553.163.1.el8_10ALSA-2026:67468
AlmaLinux:9kernel-debug-modules5.14.0-687.51.1.el9_8ALSA-2026:71232
AlmaLinux:9kernel-debug-modules-core5.14.0-687.51.1.el9_8ALSA-2026:71232
AlmaLinux:8kernel-debug-modules-extra4.18.0-553.163.1.el8_10ALSA-2026:67468
AlmaLinux:10kernel-devel6.12.0-211.59.1.el10_2ALSA-2026:71233
AlmaLinux:8kernel-devel4.18.0-553.163.1.el8_10ALSA-2026:67468
AlmaLinux:10kernel-devel-matched6.12.0-211.59.1.el10_2ALSA-2026:71233
AlmaLinux:10kernel-doc6.12.0-211.59.1.el10_2ALSA-2026:71233
AlmaLinux:8kernel-doc4.18.0-553.163.1.el8_10ALSA-2026:67468
AlmaLinux:10kernel-headers6.12.0-211.59.1.el10_2ALSA-2026:71233
AlmaLinux:8kernel-headers4.18.0-553.163.1.el8_10ALSA-2026:67468
AlmaLinux:8kernel-modules4.18.0-553.163.1.el8_10ALSA-2026:67468
AlmaLinux:8kernel-modules-extra4.18.0-553.163.1.el8_10ALSA-2026:67468
AlmaLinux:8kernel-rt4.18.0-553.163.1.rt7.504.el8_10ALSA-2026:67469
AlmaLinux:8kernel-rt-core4.18.0-553.163.1.rt7.504.el8_10ALSA-2026:67469
AlmaLinux:8kernel-rt-debug4.18.0-553.163.1.rt7.504.el8_10ALSA-2026:67469
AlmaLinux:8kernel-rt-debug-core4.18.0-553.163.1.rt7.504.el8_10ALSA-2026:67469
AlmaLinux:8kernel-rt-debug-devel4.18.0-553.163.1.rt7.504.el8_10ALSA-2026:67469
AlmaLinux:8kernel-rt-debug-modules4.18.0-553.163.1.rt7.504.el8_10ALSA-2026:67469
AlmaLinux:8kernel-rt-debug-modules-extra4.18.0-553.163.1.rt7.504.el8_10ALSA-2026:67469
AlmaLinux:8kernel-rt-devel4.18.0-553.163.1.rt7.504.el8_10ALSA-2026:67469
AlmaLinux:8kernel-rt-modules4.18.0-553.163.1.rt7.504.el8_10ALSA-2026:67469
AlmaLinux:8kernel-rt-modules-extra4.18.0-553.163.1.rt7.504.el8_10ALSA-2026:67469
AlmaLinux:8kernel-tools4.18.0-553.163.1.el8_10ALSA-2026:67468
AlmaLinux:8kernel-tools-libs4.18.0-553.163.1.el8_10ALSA-2026:67468
AlmaLinux:8kernel-tools-libs-devel4.18.0-553.163.1.el8_10ALSA-2026:67468
AlmaLinux:8kernel-zfcpdump4.18.0-553.163.1.el8_10ALSA-2026:67468
AlmaLinux:8kernel-zfcpdump-core4.18.0-553.163.1.el8_10ALSA-2026:67468
AlmaLinux:10kernel-zfcpdump-devel6.12.0-211.59.1.el10_2ALSA-2026:71233
AlmaLinux:8kernel-zfcpdump-devel4.18.0-553.163.1.el8_10ALSA-2026:67468
AlmaLinux:10kernel-zfcpdump-devel-matched6.12.0-211.59.1.el10_2ALSA-2026:71233
AlmaLinux:8kernel-zfcpdump-modules4.18.0-553.163.1.el8_10ALSA-2026:67468
AlmaLinux:8kernel-zfcpdump-modules-extra4.18.0-553.163.1.el8_10ALSA-2026:67468
AlmaLinux:10perf6.12.0-211.59.1.el10_2ALSA-2026:71233
AlmaLinux:8perf4.18.0-553.163.1.el8_10ALSA-2026:67468
AlmaLinux:10python3-perf6.12.0-211.59.1.el10_2ALSA-2026:71233
AlmaLinux:8python3-perf4.18.0-553.163.1.el8_10ALSA-2026:67468
Debian:13linux6.12.95-1DEBIAN-CVE-2026-63802
Debian:14linux7.1.3-1DEBIAN-CVE-2026-63802
Rocky Linux:8kernel0:4.18.0-553.163.1.el8_10RLSA-2026:67468
Rocky Linux:9kernel0:5.14.0-687.51.1.el9_8RLSA-2026:71232
Rocky Linux:8kernel-rt0:4.18.0-553.163.1.rt7.504.el8_10RLSA-2026:67469
Ubuntu:24.04:LTSlinux6.8.0-147.147UBUNTU-CVE-2026-63802
Ubuntu:26.04:LTSlinux7.0.0-31.31UBUNTU-CVE-2026-63802
Ubuntu:22.04:LTSlinux-allwinner-5.19no fix listedUBUNTU-CVE-2026-63802
Ubuntu:24.04:LTSlinux-aws6.8.0-1067.70UBUNTU-CVE-2026-63802
Ubuntu:26.04:LTSlinux-aws7.0.0-1012.12UBUNTU-CVE-2026-63802
Ubuntu:22.04:LTSlinux-aws-5.19no fix listedUBUNTU-CVE-2026-63802
Ubuntu:24.04:LTSlinux-aws-6.14no fix listedUBUNTU-CVE-2026-63802
Ubuntu:24.04:LTSlinux-aws-6.17no fix listedUBUNTU-CVE-2026-63802
Ubuntu:22.04:LTSlinux-aws-6.2no fix listedUBUNTU-CVE-2026-63802
Ubuntu:22.04:LTSlinux-aws-6.5no fix listedUBUNTU-CVE-2026-63802
Ubuntu:22.04:LTSlinux-aws-6.8no fix listedUBUNTU-CVE-2026-63802
Ubuntu:24.04:LTSlinux-aws-7.07.0.0-1012.12~24.04.1UBUNTU-CVE-2026-63802
Ubuntu:24.04:LTSlinux-azure6.8.0-1071.79UBUNTU-CVE-2026-63802
Ubuntu:26.04:LTSlinux-azure7.0.0-1014.14UBUNTU-CVE-2026-63802
Ubuntu:22.04:LTSlinux-azure-5.19no fix listedUBUNTU-CVE-2026-63802
Ubuntu:24.04:LTSlinux-azure-6.11no fix listedUBUNTU-CVE-2026-63802
Ubuntu:24.04:LTSlinux-azure-6.14no fix listedUBUNTU-CVE-2026-63802
Ubuntu:24.04:LTSlinux-azure-6.17no fix listedUBUNTU-CVE-2026-63802
Ubuntu:22.04:LTSlinux-azure-6.2no fix listedUBUNTU-CVE-2026-63802
Ubuntu:22.04:LTSlinux-azure-6.5no fix listedUBUNTU-CVE-2026-63802
Ubuntu:22.04:LTSlinux-azure-6.8no fix listedUBUNTU-CVE-2026-63802
Ubuntu:24.04:LTSlinux-azure-7.07.0.0-1014.14~24.04.1UBUNTU-CVE-2026-63802
Ubuntu:24.04:LTSlinux-azure-fde6.8.0-1069.76UBUNTU-CVE-2026-63802
Ubuntu:26.04:LTSlinux-azure-fde7.0.0-1013.13UBUNTU-CVE-2026-63802
Ubuntu:22.04:LTSlinux-azure-fde-5.19no fix listedUBUNTU-CVE-2026-63802
Ubuntu:24.04:LTSlinux-azure-fde-6.14no fix listedUBUNTU-CVE-2026-63802
Ubuntu:24.04:LTSlinux-azure-fde-6.17no fix listedUBUNTU-CVE-2026-63802
Ubuntu:22.04:LTSlinux-azure-fde-6.2no fix listedUBUNTU-CVE-2026-63802
Ubuntu:22.04:LTSlinux-azure-fde-6.8no fix listedUBUNTU-CVE-2026-63802
Ubuntu:24.04:LTSlinux-azure-fde-7.07.0.0-1013.13~24.04.1UBUNTU-CVE-2026-63802
Ubuntu:24.04:LTSlinux-azure-nvidiano fix listedUBUNTU-CVE-2026-63802
Ubuntu:24.04:LTSlinux-azure-nvidia-6.14no fix listedUBUNTU-CVE-2026-63802
Ubuntu:24.04:LTSlinux-gcp6.8.0-1071.79UBUNTU-CVE-2026-63802
Ubuntu:26.04:LTSlinux-gcp7.0.0-1011.11UBUNTU-CVE-2026-63802
Ubuntu:22.04:LTSlinux-gcp-5.19no fix listedUBUNTU-CVE-2026-63802
Ubuntu:24.04:LTSlinux-gcp-6.11no fix listedUBUNTU-CVE-2026-63802
Ubuntu:24.04:LTSlinux-gcp-6.14no fix listedUBUNTU-CVE-2026-63802
Ubuntu:24.04:LTSlinux-gcp-6.17no fix listedUBUNTU-CVE-2026-63802
Ubuntu:22.04:LTSlinux-gcp-6.2no fix listedUBUNTU-CVE-2026-63802
Ubuntu:22.04:LTSlinux-gcp-6.5no fix listedUBUNTU-CVE-2026-63802
Ubuntu:22.04:LTSlinux-gcp-6.8no fix listedUBUNTU-CVE-2026-63802
Ubuntu:24.04:LTSlinux-gcp-7.07.0.0-1011.11~24.04.1UBUNTU-CVE-2026-63802
Ubuntu:24.04:LTSlinux-gke6.8.0-1066.74UBUNTU-CVE-2026-63802
Ubuntu:26.04:LTSlinux-gke7.0.0-1006.7UBUNTU-CVE-2026-63802
Ubuntu:24.04:LTSlinux-gkeop6.8.0-1052.56UBUNTU-CVE-2026-63802
Ubuntu:22.04:LTSlinux-hwe-5.19no fix listedUBUNTU-CVE-2026-63802
Ubuntu:24.04:LTSlinux-hwe-6.11no fix listedUBUNTU-CVE-2026-63802
Ubuntu:24.04:LTSlinux-hwe-6.14no fix listedUBUNTU-CVE-2026-63802
Ubuntu:24.04:LTSlinux-hwe-6.17no fix listedUBUNTU-CVE-2026-63802
Ubuntu:22.04:LTSlinux-hwe-6.2no fix listedUBUNTU-CVE-2026-63802
Ubuntu:22.04:LTSlinux-hwe-6.5no fix listedUBUNTU-CVE-2026-63802
Ubuntu:22.04:LTSlinux-hwe-6.8no fix listedUBUNTU-CVE-2026-63802
Ubuntu:24.04:LTSlinux-hwe-7.07.0.0-31.31~24.04.1UBUNTU-CVE-2026-63802
Ubuntu:24.04:LTSlinux-ibm6.8.0-1067.68UBUNTU-CVE-2026-63802
Ubuntu:26.04:LTSlinux-ibm7.0.0-1013.13UBUNTU-CVE-2026-63802
Ubuntu:22.04:LTSlinux-ibm-6.8no fix listedUBUNTU-CVE-2026-63802
Ubuntu:22.04:LTSlinux-intel-iot-realtimeno fix listedUBUNTU-CVE-2026-63802
Ubuntu:24.04:LTSlinux-lowlatency6.8.0-147.147.1UBUNTU-CVE-2026-63802
Ubuntu:22.04:LTSlinux-lowlatency-hwe-5.19no fix listedUBUNTU-CVE-2026-63802
Ubuntu:24.04:LTSlinux-lowlatency-hwe-6.11no fix listedUBUNTU-CVE-2026-63802
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.2no fix listedUBUNTU-CVE-2026-63802
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.5no fix listedUBUNTU-CVE-2026-63802
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.8no fix listedUBUNTU-CVE-2026-63802
Ubuntu:24.04:LTSlinux-nvidiano fix listedUBUNTU-CVE-2026-63802
Ubuntu:26.04:LTSlinux-nvidia7.0.0-1018.18UBUNTU-CVE-2026-63802
Ubuntu:24.04:LTSlinux-nvidia-6.11no fix listedUBUNTU-CVE-2026-63802
Ubuntu:24.04:LTSlinux-nvidia-6.17no fix listedUBUNTU-CVE-2026-63802
Ubuntu:22.04:LTSlinux-nvidia-6.2no fix listedUBUNTU-CVE-2026-63802
Ubuntu:22.04:LTSlinux-nvidia-6.5no fix listedUBUNTU-CVE-2026-63802
Ubuntu:22.04:LTSlinux-nvidia-6.8no fix listedUBUNTU-CVE-2026-63802
Ubuntu:24.04:LTSlinux-nvidia-7.07.0.0-1018.18~24.04.1UBUNTU-CVE-2026-63802
Ubuntu:26.04:LTSlinux-nvidia-bos7.0.0-2018.18UBUNTU-CVE-2026-63802
Ubuntu:24.04:LTSlinux-nvidia-lowlatencyno fix listedUBUNTU-CVE-2026-63802
Ubuntu:24.04:LTSlinux-nvidia-tegra6.8.0-1036.39UBUNTU-CVE-2026-63802
Ubuntu:22.04:LTSlinux-oem-5.17no fix listedUBUNTU-CVE-2026-63802
Ubuntu:22.04:LTSlinux-oem-6.0no fix listedUBUNTU-CVE-2026-63802
Ubuntu:22.04:LTSlinux-oem-6.1no fix listedUBUNTU-CVE-2026-63802
Ubuntu:24.04:LTSlinux-oem-6.11no fix listedUBUNTU-CVE-2026-63802
Ubuntu:24.04:LTSlinux-oem-6.14no fix listedUBUNTU-CVE-2026-63802
Ubuntu:24.04:LTSlinux-oem-6.17no fix listedUBUNTU-CVE-2026-63802
Ubuntu:22.04:LTSlinux-oem-6.5no fix listedUBUNTU-CVE-2026-63802
Ubuntu:24.04:LTSlinux-oem-6.8no fix listedUBUNTU-CVE-2026-63802
Ubuntu:26.04:LTSlinux-oem-7.07.0.0-1013.13UBUNTU-CVE-2026-63802
Ubuntu:24.04:LTSlinux-oracle6.8.0-1064.67UBUNTU-CVE-2026-63802
Ubuntu:26.04:LTSlinux-oracle7.0.0-1011.11UBUNTU-CVE-2026-63802
Ubuntu:24.04:LTSlinux-oracle-6.14no fix listedUBUNTU-CVE-2026-63802
Ubuntu:24.04:LTSlinux-oracle-6.17no fix listedUBUNTU-CVE-2026-63802
Ubuntu:22.04:LTSlinux-oracle-6.5no fix listedUBUNTU-CVE-2026-63802
Ubuntu:22.04:LTSlinux-oracle-6.8no fix listedUBUNTU-CVE-2026-63802
Ubuntu:24.04:LTSlinux-oracle-7.07.0.0-1011.11~24.04.1UBUNTU-CVE-2026-63802
Ubuntu:24.04:LTSlinux-raspino fix listedUBUNTU-CVE-2026-63802
Ubuntu:26.04:LTSlinux-raspi7.0.0-1019.19UBUNTU-CVE-2026-63802
Ubuntu:24.04:LTSlinux-raspi-realtimeno fix listedUBUNTU-CVE-2026-63802
Ubuntu:22.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-63802
Ubuntu:24.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-63802
Ubuntu:26.04:LTSlinux-realtime7.0.0-31.31.1UBUNTU-CVE-2026-63802
Ubuntu:22.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2026-63802
Ubuntu:24.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2026-63802
Ubuntu:26.04:LTSlinux-riscv7.0.0-31.31.1UBUNTU-CVE-2026-63802
Ubuntu:22.04:LTSlinux-riscv-5.19no fix listedUBUNTU-CVE-2026-63802
Ubuntu:24.04:LTSlinux-riscv-6.14no fix listedUBUNTU-CVE-2026-63802
Ubuntu:24.04:LTSlinux-riscv-6.17no fix listedUBUNTU-CVE-2026-63802
Ubuntu:22.04:LTSlinux-riscv-6.5no fix listedUBUNTU-CVE-2026-63802
Ubuntu:22.04:LTSlinux-riscv-6.8no fix listedUBUNTU-CVE-2026-63802
Ubuntu:24.04:LTSlinux-riscv-7.07.0.0-31.31.1~24.04.1UBUNTU-CVE-2026-63802
Ubuntu:22.04:LTSlinux-starfive-5.19no fix listedUBUNTU-CVE-2026-63802
Ubuntu:22.04:LTSlinux-starfive-6.2no fix listedUBUNTU-CVE-2026-63802
Ubuntu:22.04:LTSlinux-starfive-6.5no fix listedUBUNTU-CVE-2026-63802
Ubuntu:24.04:LTSlinux-vmware6.8.0-1008.8UBUNTU-CVE-2026-63802
Ubuntu:24.04:LTSlinux-xilinxno fix listedUBUNTU-CVE-2026-63802

Affected products (as reported)

VendorProductVersions
Linux Linux 20cb1c2fb7568a6054c55defe044311397e01ddb – before 96e545410c4f74c89d496c1d5d9ef8d08f14368b20cb1c2fb7568a6054c55defe044311397e01ddb – before bbebd9425cad3573d1527441753899b926525a0f20cb1c2fb7568a6054c55defe044311397e01ddb – before 5e5b7f2ef854936e95dceb6a2fdfefcb7152d2c620cb1c2fb7568a6054c55defe044311397e01ddb – before afebe44facc48a61761e885bbb7f0380d4a603ec20cb1c2fb7568a6054c55defe044311397e01ddb – before 0ab5ee5a1badb58cbb2242617cb01a4972b1f2a20f6090d90f627d8c58f939067d6c6821ce1b3c686.3.9 – before 6.4
Linux Linux 6.4

Weakness: CWE-362 · Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

References