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Vulnerability · Published Jul 25, 2026 · Assigned by Linux

CVE-2026-64383smb: client: fix double-free in SMB2_flush() replay

Critical 9.8

In plain English

A critical-severity double free 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 0.5% (higher than 40% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)9.8Critical
Exploit odds (30 days)0.5%top 60.2% 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: smb: client: fix double-free in SMB2_flush() replay SMB2_flush() keeps its response buffer bookkeeping across replay attempts. If a replayable flush response is received and the retry then fails before cifs_send_recv() stores a replacement response, flush_exit will free the stale response pointer a second time. Reinitialize resp_buftype and rsp_iov at the top of the replay loop so cleanup only acts on response state produced by the current attempt. This fixes a double-free without changing replay handling for successful requests.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
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:9kernel-abi-stablelists5.14.0-687.51.1.el9_8ALSA-2026:71232
AlmaLinux:9kernel-core5.14.0-687.51.1.el9_8ALSA-2026:71232
AlmaLinux:9kernel-debug5.14.0-687.51.1.el9_8ALSA-2026:71232
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:10kernel-debug-devel-matched6.12.0-211.59.1.el10_2ALSA-2026:71233
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:10kernel-devel6.12.0-211.59.1.el10_2ALSA-2026:71233
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:10kernel-headers6.12.0-211.59.1.el10_2ALSA-2026:71233
AlmaLinux:10kernel-zfcpdump-devel6.12.0-211.59.1.el10_2ALSA-2026:71233
AlmaLinux:10kernel-zfcpdump-devel-matched6.12.0-211.59.1.el10_2ALSA-2026:71233
AlmaLinux:10perf6.12.0-211.59.1.el10_2ALSA-2026:71233
AlmaLinux:10python3-perf6.12.0-211.59.1.el10_2ALSA-2026:71233
Debian:13linux6.12.96-1DEBIAN-CVE-2026-64383
Debian:14linux7.1.4-1DEBIAN-CVE-2026-64383
Debian:12linux-6.126.12.100-1~deb12u1DEBIAN-CVE-2026-64383
Rocky Linux:9kernel0:5.14.0-687.51.1.el9_8RLSA-2026:71232
Ubuntu:24.04:LTSlinux6.8.0-147.147UBUNTU-CVE-2026-64383
Ubuntu:26.04:LTSlinux7.0.0-31.31UBUNTU-CVE-2026-64383
Ubuntu:22.04:LTSlinux-allwinner-5.19no fix listedUBUNTU-CVE-2026-64383
Ubuntu:24.04:LTSlinux-aws6.8.0-1067.70UBUNTU-CVE-2026-64383
Ubuntu:26.04:LTSlinux-aws7.0.0-1012.12UBUNTU-CVE-2026-64383
Ubuntu:22.04:LTSlinux-aws-5.19no fix listedUBUNTU-CVE-2026-64383
Ubuntu:24.04:LTSlinux-aws-6.14no fix listedUBUNTU-CVE-2026-64383
Ubuntu:24.04:LTSlinux-aws-6.17no fix listedUBUNTU-CVE-2026-64383
Ubuntu:22.04:LTSlinux-aws-6.2no fix listedUBUNTU-CVE-2026-64383
Ubuntu:22.04:LTSlinux-aws-6.5no fix listedUBUNTU-CVE-2026-64383
Ubuntu:22.04:LTSlinux-aws-6.8no fix listedUBUNTU-CVE-2026-64383
Ubuntu:24.04:LTSlinux-aws-7.07.0.0-1012.12~24.04.1UBUNTU-CVE-2026-64383
Ubuntu:24.04:LTSlinux-azure6.8.0-1071.79UBUNTU-CVE-2026-64383
Ubuntu:26.04:LTSlinux-azure7.0.0-1014.14UBUNTU-CVE-2026-64383
Ubuntu:22.04:LTSlinux-azure-5.19no fix listedUBUNTU-CVE-2026-64383
Ubuntu:24.04:LTSlinux-azure-6.11no fix listedUBUNTU-CVE-2026-64383
Ubuntu:24.04:LTSlinux-azure-6.14no fix listedUBUNTU-CVE-2026-64383
Ubuntu:24.04:LTSlinux-azure-6.17no fix listedUBUNTU-CVE-2026-64383
Ubuntu:22.04:LTSlinux-azure-6.2no fix listedUBUNTU-CVE-2026-64383
Ubuntu:22.04:LTSlinux-azure-6.5no fix listedUBUNTU-CVE-2026-64383
Ubuntu:22.04:LTSlinux-azure-6.8no fix listedUBUNTU-CVE-2026-64383
Ubuntu:24.04:LTSlinux-azure-7.07.0.0-1014.14~24.04.1UBUNTU-CVE-2026-64383
Ubuntu:24.04:LTSlinux-azure-fde6.8.0-1069.76UBUNTU-CVE-2026-64383
Ubuntu:26.04:LTSlinux-azure-fde7.0.0-1013.13UBUNTU-CVE-2026-64383
Ubuntu:22.04:LTSlinux-azure-fde-5.19no fix listedUBUNTU-CVE-2026-64383
Ubuntu:24.04:LTSlinux-azure-fde-6.14no fix listedUBUNTU-CVE-2026-64383
Ubuntu:24.04:LTSlinux-azure-fde-6.17no fix listedUBUNTU-CVE-2026-64383
Ubuntu:22.04:LTSlinux-azure-fde-6.2no fix listedUBUNTU-CVE-2026-64383
Ubuntu:22.04:LTSlinux-azure-fde-6.8no fix listedUBUNTU-CVE-2026-64383
Ubuntu:24.04:LTSlinux-azure-fde-7.07.0.0-1013.13~24.04.1UBUNTU-CVE-2026-64383
Ubuntu:24.04:LTSlinux-azure-nvidiano fix listedUBUNTU-CVE-2026-64383
Ubuntu:24.04:LTSlinux-azure-nvidia-6.14no fix listedUBUNTU-CVE-2026-64383
Ubuntu:24.04:LTSlinux-gcp6.8.0-1071.79UBUNTU-CVE-2026-64383
Ubuntu:26.04:LTSlinux-gcp7.0.0-1011.11UBUNTU-CVE-2026-64383
Ubuntu:22.04:LTSlinux-gcp-5.19no fix listedUBUNTU-CVE-2026-64383
Ubuntu:24.04:LTSlinux-gcp-6.11no fix listedUBUNTU-CVE-2026-64383
Ubuntu:24.04:LTSlinux-gcp-6.14no fix listedUBUNTU-CVE-2026-64383
Ubuntu:24.04:LTSlinux-gcp-6.17no fix listedUBUNTU-CVE-2026-64383
Ubuntu:22.04:LTSlinux-gcp-6.2no fix listedUBUNTU-CVE-2026-64383
Ubuntu:22.04:LTSlinux-gcp-6.5no fix listedUBUNTU-CVE-2026-64383
Ubuntu:22.04:LTSlinux-gcp-6.8no fix listedUBUNTU-CVE-2026-64383
Ubuntu:24.04:LTSlinux-gcp-7.07.0.0-1011.11~24.04.1UBUNTU-CVE-2026-64383
Ubuntu:24.04:LTSlinux-gke6.8.0-1066.74UBUNTU-CVE-2026-64383
Ubuntu:26.04:LTSlinux-gke7.0.0-1006.7UBUNTU-CVE-2026-64383
Ubuntu:24.04:LTSlinux-gkeop6.8.0-1052.56UBUNTU-CVE-2026-64383
Ubuntu:22.04:LTSlinux-hwe-5.19no fix listedUBUNTU-CVE-2026-64383
Ubuntu:24.04:LTSlinux-hwe-6.11no fix listedUBUNTU-CVE-2026-64383
Ubuntu:24.04:LTSlinux-hwe-6.14no fix listedUBUNTU-CVE-2026-64383
Ubuntu:24.04:LTSlinux-hwe-6.17no fix listedUBUNTU-CVE-2026-64383
Ubuntu:22.04:LTSlinux-hwe-6.2no fix listedUBUNTU-CVE-2026-64383
Ubuntu:22.04:LTSlinux-hwe-6.5no fix listedUBUNTU-CVE-2026-64383
Ubuntu:22.04:LTSlinux-hwe-6.8no fix listedUBUNTU-CVE-2026-64383
Ubuntu:24.04:LTSlinux-hwe-7.07.0.0-31.31~24.04.1UBUNTU-CVE-2026-64383
Ubuntu:24.04:LTSlinux-ibm6.8.0-1067.68UBUNTU-CVE-2026-64383
Ubuntu:26.04:LTSlinux-ibm7.0.0-1013.13UBUNTU-CVE-2026-64383
Ubuntu:22.04:LTSlinux-ibm-6.8no fix listedUBUNTU-CVE-2026-64383
Ubuntu:22.04:LTSlinux-intel-iot-realtimeno fix listedUBUNTU-CVE-2026-64383
Ubuntu:24.04:LTSlinux-lowlatency6.8.0-147.147.1UBUNTU-CVE-2026-64383
Ubuntu:22.04:LTSlinux-lowlatency-hwe-5.19no fix listedUBUNTU-CVE-2026-64383
Ubuntu:24.04:LTSlinux-lowlatency-hwe-6.11no fix listedUBUNTU-CVE-2026-64383
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.2no fix listedUBUNTU-CVE-2026-64383
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.5no fix listedUBUNTU-CVE-2026-64383
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.8no fix listedUBUNTU-CVE-2026-64383
Ubuntu:24.04:LTSlinux-nvidiano fix listedUBUNTU-CVE-2026-64383
Ubuntu:26.04:LTSlinux-nvidia7.0.0-1018.18UBUNTU-CVE-2026-64383
Ubuntu:24.04:LTSlinux-nvidia-6.11no fix listedUBUNTU-CVE-2026-64383
Ubuntu:24.04:LTSlinux-nvidia-6.17no fix listedUBUNTU-CVE-2026-64383
Ubuntu:22.04:LTSlinux-nvidia-6.2no fix listedUBUNTU-CVE-2026-64383
Ubuntu:22.04:LTSlinux-nvidia-6.5no fix listedUBUNTU-CVE-2026-64383
Ubuntu:22.04:LTSlinux-nvidia-6.8no fix listedUBUNTU-CVE-2026-64383
Ubuntu:24.04:LTSlinux-nvidia-7.07.0.0-1018.18~24.04.1UBUNTU-CVE-2026-64383
Ubuntu:26.04:LTSlinux-nvidia-bos7.0.0-2018.18UBUNTU-CVE-2026-64383
Ubuntu:24.04:LTSlinux-nvidia-lowlatencyno fix listedUBUNTU-CVE-2026-64383
Ubuntu:24.04:LTSlinux-nvidia-tegra6.8.0-1035.38UBUNTU-CVE-2026-64383
Ubuntu:22.04:LTSlinux-oem-5.17no fix listedUBUNTU-CVE-2026-64383
Ubuntu:22.04:LTSlinux-oem-6.0no fix listedUBUNTU-CVE-2026-64383
Ubuntu:22.04:LTSlinux-oem-6.1no fix listedUBUNTU-CVE-2026-64383
Ubuntu:24.04:LTSlinux-oem-6.11no fix listedUBUNTU-CVE-2026-64383
Ubuntu:24.04:LTSlinux-oem-6.14no fix listedUBUNTU-CVE-2026-64383
Ubuntu:24.04:LTSlinux-oem-6.17no fix listedUBUNTU-CVE-2026-64383
Ubuntu:22.04:LTSlinux-oem-6.5no fix listedUBUNTU-CVE-2026-64383
Ubuntu:24.04:LTSlinux-oem-6.8no fix listedUBUNTU-CVE-2026-64383
Ubuntu:26.04:LTSlinux-oem-7.07.0.0-1013.13UBUNTU-CVE-2026-64383
Ubuntu:24.04:LTSlinux-oracle6.8.0-1064.67UBUNTU-CVE-2026-64383
Ubuntu:26.04:LTSlinux-oracle7.0.0-1011.11UBUNTU-CVE-2026-64383
Ubuntu:24.04:LTSlinux-oracle-6.14no fix listedUBUNTU-CVE-2026-64383
Ubuntu:24.04:LTSlinux-oracle-6.17no fix listedUBUNTU-CVE-2026-64383
Ubuntu:22.04:LTSlinux-oracle-6.5no fix listedUBUNTU-CVE-2026-64383
Ubuntu:22.04:LTSlinux-oracle-6.8no fix listedUBUNTU-CVE-2026-64383
Ubuntu:24.04:LTSlinux-oracle-7.07.0.0-1011.11~24.04.1UBUNTU-CVE-2026-64383
Ubuntu:24.04:LTSlinux-raspino fix listedUBUNTU-CVE-2026-64383
Ubuntu:26.04:LTSlinux-raspi7.0.0-1019.19UBUNTU-CVE-2026-64383
Ubuntu:24.04:LTSlinux-raspi-realtimeno fix listedUBUNTU-CVE-2026-64383
Ubuntu:22.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-64383
Ubuntu:24.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-64383
Ubuntu:26.04:LTSlinux-realtime7.0.0-31.31.1UBUNTU-CVE-2026-64383
Ubuntu:22.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2026-64383
Ubuntu:24.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2026-64383
Ubuntu:26.04:LTSlinux-riscv7.0.0-31.31.1UBUNTU-CVE-2026-64383
Ubuntu:22.04:LTSlinux-riscv-5.19no fix listedUBUNTU-CVE-2026-64383
Ubuntu:24.04:LTSlinux-riscv-6.14no fix listedUBUNTU-CVE-2026-64383
Ubuntu:24.04:LTSlinux-riscv-6.17no fix listedUBUNTU-CVE-2026-64383
Ubuntu:22.04:LTSlinux-riscv-6.5no fix listedUBUNTU-CVE-2026-64383
Ubuntu:22.04:LTSlinux-riscv-6.8no fix listedUBUNTU-CVE-2026-64383
Ubuntu:24.04:LTSlinux-riscv-7.07.0.0-31.31.1~24.04.1UBUNTU-CVE-2026-64383
Ubuntu:22.04:LTSlinux-starfive-5.19no fix listedUBUNTU-CVE-2026-64383
Ubuntu:22.04:LTSlinux-starfive-6.2no fix listedUBUNTU-CVE-2026-64383
Ubuntu:22.04:LTSlinux-starfive-6.5no fix listedUBUNTU-CVE-2026-64383
Ubuntu:24.04:LTSlinux-vmware6.8.0-1008.8UBUNTU-CVE-2026-64383
Ubuntu:24.04:LTSlinux-xilinxno fix listedUBUNTU-CVE-2026-64383

Affected products (as reported)

VendorProductVersions
Linux Linux 433042a91f9373241307725b52de573933ffedbf – before 6e27f40b682a5e42a2daae3ce6d96f0e0e16dedb4f1fffa2376922f3d1d506e49c0fd445b023a28e – before 878757163eea684750107a31ea134c103863515d4f1fffa2376922f3d1d506e49c0fd445b023a28e – before 3407240cde132a4b72d6429a2625a09a2f78adaf4f1fffa2376922f3d1d506e49c0fd445b023a28e – before 013a9a3da46c5dabcf18f65ea6a47874ba12a15d4f1fffa2376922f3d1d506e49c0fd445b023a28e – before 4be31c943a3a27a5a0251dbb8f5cb89059ec3d5a6.6.32 – before 6.6.145
Linux Linux 6.8

Weakness: CWE-415 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

References