Vulnerability · Published Oct 6, 2026 · Assigned by Linux

CVE-2026-98261cifs: Fix server use-after-free in cifs_chan_skip_or_disable()

High 8.1

In plain English

A high-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 35% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)8.1High
Exploit odds (30 days)0.4%top 65.0% 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: cifs: Fix server use-after-free in cifs_chan_skip_or_disable() When a secondary channel is no longer supported by the server, cifs_chan_skip_or_disable() drops the channel reference with cifs_put_tcp_session() and then continues to use the server pointer by calling cifs_signal_cifsd_for_reconnect() on it and reading its primary_server pointer. cifs_put_tcp_session() can drop the last reference of the channel and tear it down, so both the channel and the primary server (whose reference is also dropped by cifs_put_tcp_session()) can be freed before they are signaled for reconnect. Signal the channel and the primary server and capture the primary server pointer before dropping the channel reference with cifs_put_tcp_session().

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:13linux6.12.113-1DEBIAN-CVE-2026-98261
Debian:14linux7.2.8-1DEBIAN-CVE-2026-98261
Debian:12linux-6.126.12.113-1~deb12u1DEBIAN-CVE-2026-98261
Ubuntu:24.04:LTSlinuxno fix listedUBUNTU-CVE-2026-98261
Ubuntu:26.04:LTSlinux7.0.0-42.42UBUNTU-CVE-2026-98261
Ubuntu:22.04:LTSlinux-allwinner-5.19no fix listedUBUNTU-CVE-2026-98261
Ubuntu:24.04:LTSlinux-awsno fix listedUBUNTU-CVE-2026-98261
Ubuntu:26.04:LTSlinux-aws7.0.0-1016.17UBUNTU-CVE-2026-98261
Ubuntu:22.04:LTSlinux-aws-5.19no fix listedUBUNTU-CVE-2026-98261
Ubuntu:24.04:LTSlinux-aws-6.14no fix listedUBUNTU-CVE-2026-98261
Ubuntu:24.04:LTSlinux-aws-6.17no fix listedUBUNTU-CVE-2026-98261
Ubuntu:22.04:LTSlinux-aws-6.2no fix listedUBUNTU-CVE-2026-98261
Ubuntu:22.04:LTSlinux-aws-6.5no fix listedUBUNTU-CVE-2026-98261
Ubuntu:22.04:LTSlinux-aws-6.8no fix listedUBUNTU-CVE-2026-98261
Ubuntu:24.04:LTSlinux-aws-7.0no fix listedUBUNTU-CVE-2026-98261
Ubuntu:22.04:LTSlinux-azureno fix listedUBUNTU-CVE-2026-98261
Ubuntu:24.04:LTSlinux-azureno fix listedUBUNTU-CVE-2026-98261
Ubuntu:26.04:LTSlinux-azureno fix listedUBUNTU-CVE-2026-98261
Ubuntu:22.04:LTSlinux-azure-5.19no fix listedUBUNTU-CVE-2026-98261
Ubuntu:24.04:LTSlinux-azure-6.11no fix listedUBUNTU-CVE-2026-98261
Ubuntu:24.04:LTSlinux-azure-6.14no fix listedUBUNTU-CVE-2026-98261
Ubuntu:24.04:LTSlinux-azure-6.17no fix listedUBUNTU-CVE-2026-98261
Ubuntu:22.04:LTSlinux-azure-6.2no fix listedUBUNTU-CVE-2026-98261
Ubuntu:22.04:LTSlinux-azure-6.5no fix listedUBUNTU-CVE-2026-98261
Ubuntu:22.04:LTSlinux-azure-6.8no fix listedUBUNTU-CVE-2026-98261
Ubuntu:24.04:LTSlinux-azure-7.0no fix listedUBUNTU-CVE-2026-98261
Ubuntu:22.04:LTSlinux-azure-fdeno fix listedUBUNTU-CVE-2026-98261
Ubuntu:24.04:LTSlinux-azure-fdeno fix listedUBUNTU-CVE-2026-98261
Ubuntu:26.04:LTSlinux-azure-fdeno fix listedUBUNTU-CVE-2026-98261
Ubuntu:22.04:LTSlinux-azure-fde-5.19no fix listedUBUNTU-CVE-2026-98261
Ubuntu:24.04:LTSlinux-azure-fde-6.14no fix listedUBUNTU-CVE-2026-98261
Ubuntu:24.04:LTSlinux-azure-fde-6.17no fix listedUBUNTU-CVE-2026-98261
Ubuntu:22.04:LTSlinux-azure-fde-6.2no fix listedUBUNTU-CVE-2026-98261
Ubuntu:22.04:LTSlinux-azure-fde-6.8no fix listedUBUNTU-CVE-2026-98261
Ubuntu:24.04:LTSlinux-azure-fde-7.0no fix listedUBUNTU-CVE-2026-98261
Ubuntu:24.04:LTSlinux-azure-nvidiano fix listedUBUNTU-CVE-2026-98261
Ubuntu:24.04:LTSlinux-azure-nvidia-6.14no fix listedUBUNTU-CVE-2026-98261
Ubuntu:24.04:LTSlinux-gcpno fix listedUBUNTU-CVE-2026-98261
Ubuntu:26.04:LTSlinux-gcp7.0.0-1016.18UBUNTU-CVE-2026-98261
Ubuntu:22.04:LTSlinux-gcp-5.19no fix listedUBUNTU-CVE-2026-98261
Ubuntu:24.04:LTSlinux-gcp-6.11no fix listedUBUNTU-CVE-2026-98261
Ubuntu:24.04:LTSlinux-gcp-6.14no fix listedUBUNTU-CVE-2026-98261
Ubuntu:24.04:LTSlinux-gcp-6.17no fix listedUBUNTU-CVE-2026-98261
Ubuntu:22.04:LTSlinux-gcp-6.2no fix listedUBUNTU-CVE-2026-98261
Ubuntu:22.04:LTSlinux-gcp-6.5no fix listedUBUNTU-CVE-2026-98261
Ubuntu:22.04:LTSlinux-gcp-6.8no fix listedUBUNTU-CVE-2026-98261
Ubuntu:24.04:LTSlinux-gcp-7.0no fix listedUBUNTU-CVE-2026-98261
Ubuntu:24.04:LTSlinux-gkeno fix listedUBUNTU-CVE-2026-98261
Ubuntu:26.04:LTSlinux-gkeno fix listedUBUNTU-CVE-2026-98261
Ubuntu:24.04:LTSlinux-gkeopno fix listedUBUNTU-CVE-2026-98261
Ubuntu:22.04:LTSlinux-hwe-5.19no fix listedUBUNTU-CVE-2026-98261
Ubuntu:24.04:LTSlinux-hwe-6.11no fix listedUBUNTU-CVE-2026-98261
Ubuntu:24.04:LTSlinux-hwe-6.14no fix listedUBUNTU-CVE-2026-98261
Ubuntu:24.04:LTSlinux-hwe-6.17no fix listedUBUNTU-CVE-2026-98261
Ubuntu:22.04:LTSlinux-hwe-6.2no fix listedUBUNTU-CVE-2026-98261
Ubuntu:22.04:LTSlinux-hwe-6.5no fix listedUBUNTU-CVE-2026-98261
Ubuntu:22.04:LTSlinux-hwe-6.8no fix listedUBUNTU-CVE-2026-98261
Ubuntu:24.04:LTSlinux-hwe-7.07.0.0-42.42~24.04.1UBUNTU-CVE-2026-98261
Ubuntu:24.04:LTSlinux-ibmno fix listedUBUNTU-CVE-2026-98261
Ubuntu:26.04:LTSlinux-ibm7.0.0-1017.17UBUNTU-CVE-2026-98261
Ubuntu:22.04:LTSlinux-ibm-6.8no fix listedUBUNTU-CVE-2026-98261
Ubuntu:22.04:LTSlinux-intel-iot-realtimeno fix listedUBUNTU-CVE-2026-98261
Ubuntu:24.04:LTSlinux-lowlatencyno fix listedUBUNTU-CVE-2026-98261
Ubuntu:22.04:LTSlinux-lowlatency-hwe-5.19no fix listedUBUNTU-CVE-2026-98261
Ubuntu:24.04:LTSlinux-lowlatency-hwe-6.11no fix listedUBUNTU-CVE-2026-98261
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.2no fix listedUBUNTU-CVE-2026-98261
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.5no fix listedUBUNTU-CVE-2026-98261
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.8no fix listedUBUNTU-CVE-2026-98261
Ubuntu:24.04:LTSlinux-nvidiano fix listedUBUNTU-CVE-2026-98261
Ubuntu:26.04:LTSlinux-nvidiano fix listedUBUNTU-CVE-2026-98261
Ubuntu:24.04:LTSlinux-nvidia-6.11no fix listedUBUNTU-CVE-2026-98261
Ubuntu:24.04:LTSlinux-nvidia-6.17no fix listedUBUNTU-CVE-2026-98261
Ubuntu:22.04:LTSlinux-nvidia-6.2no fix listedUBUNTU-CVE-2026-98261
Ubuntu:22.04:LTSlinux-nvidia-6.5no fix listedUBUNTU-CVE-2026-98261
Ubuntu:22.04:LTSlinux-nvidia-6.8no fix listedUBUNTU-CVE-2026-98261
Ubuntu:24.04:LTSlinux-nvidia-7.0no fix listedUBUNTU-CVE-2026-98261
Ubuntu:26.04:LTSlinux-nvidia-bosno fix listedUBUNTU-CVE-2026-98261
Ubuntu:24.04:LTSlinux-nvidia-lowlatencyno fix listedUBUNTU-CVE-2026-98261
Ubuntu:24.04:LTSlinux-nvidia-tegrano fix listedUBUNTU-CVE-2026-98261
Ubuntu:22.04:LTSlinux-oem-5.17no fix listedUBUNTU-CVE-2026-98261
Ubuntu:22.04:LTSlinux-oem-6.0no fix listedUBUNTU-CVE-2026-98261
Ubuntu:22.04:LTSlinux-oem-6.1no fix listedUBUNTU-CVE-2026-98261
Ubuntu:24.04:LTSlinux-oem-6.11no fix listedUBUNTU-CVE-2026-98261
Ubuntu:24.04:LTSlinux-oem-6.14no fix listedUBUNTU-CVE-2026-98261
Ubuntu:24.04:LTSlinux-oem-6.17no fix listedUBUNTU-CVE-2026-98261
Ubuntu:22.04:LTSlinux-oem-6.5no fix listedUBUNTU-CVE-2026-98261
Ubuntu:24.04:LTSlinux-oem-6.8no fix listedUBUNTU-CVE-2026-98261
Ubuntu:26.04:LTSlinux-oem-7.07.0.0-1017.17UBUNTU-CVE-2026-98261
Ubuntu:24.04:LTSlinux-oracleno fix listedUBUNTU-CVE-2026-98261
Ubuntu:26.04:LTSlinux-oracle7.0.0-1015.16UBUNTU-CVE-2026-98261
Ubuntu:24.04:LTSlinux-oracle-6.14no fix listedUBUNTU-CVE-2026-98261
Ubuntu:24.04:LTSlinux-oracle-6.17no fix listedUBUNTU-CVE-2026-98261
Ubuntu:22.04:LTSlinux-oracle-6.5no fix listedUBUNTU-CVE-2026-98261
Ubuntu:22.04:LTSlinux-oracle-6.8no fix listedUBUNTU-CVE-2026-98261
Ubuntu:24.04:LTSlinux-oracle-7.0no fix listedUBUNTU-CVE-2026-98261
Ubuntu:24.04:LTSlinux-raspino fix listedUBUNTU-CVE-2026-98261
Ubuntu:26.04:LTSlinux-raspino fix listedUBUNTU-CVE-2026-98261
Ubuntu:24.04:LTSlinux-raspi-realtimeno fix listedUBUNTU-CVE-2026-98261
Ubuntu:22.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-98261
Ubuntu:24.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-98261
Ubuntu:26.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-98261
Ubuntu:22.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2026-98261
Ubuntu:24.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2026-98261
Ubuntu:26.04:LTSlinux-riscv7.0.0-42.42.1UBUNTU-CVE-2026-98261
Ubuntu:22.04:LTSlinux-riscv-5.19no fix listedUBUNTU-CVE-2026-98261
Ubuntu:24.04:LTSlinux-riscv-6.14no fix listedUBUNTU-CVE-2026-98261
Ubuntu:24.04:LTSlinux-riscv-6.17no fix listedUBUNTU-CVE-2026-98261
Ubuntu:22.04:LTSlinux-riscv-6.5no fix listedUBUNTU-CVE-2026-98261
Ubuntu:22.04:LTSlinux-riscv-6.8no fix listedUBUNTU-CVE-2026-98261
Ubuntu:24.04:LTSlinux-riscv-7.07.0.0-42.42.1~24.04.1UBUNTU-CVE-2026-98261
Ubuntu:22.04:LTSlinux-starfive-5.19no fix listedUBUNTU-CVE-2026-98261
Ubuntu:22.04:LTSlinux-starfive-6.2no fix listedUBUNTU-CVE-2026-98261
Ubuntu:22.04:LTSlinux-starfive-6.5no fix listedUBUNTU-CVE-2026-98261
Ubuntu:24.04:LTSlinux-vmwareno fix listedUBUNTU-CVE-2026-98261
Ubuntu:24.04:LTSlinux-xilinxno fix listedUBUNTU-CVE-2026-98261

Affected products (as reported)

VendorProductVersions
Linux Linux 50e8363ecc85da49764781da90ebffe1a657b370 – before 0338489960ddad6368bce55e8adbc176c523093df591062bdbf4742b7f1622173017f19e927057b0 – before edd52eae5fcfb8433b6bb0e7cd98db438fe01227f591062bdbf4742b7f1622173017f19e927057b0 – before fcc0a935bb6e37ecbf7e4335061309f896f35780f591062bdbf4742b7f1622173017f19e927057b0 – before 7a1b27780b113583a94256d58dabfe7c0d9286e7f591062bdbf4742b7f1622173017f19e927057b0 – before 717e0a25036b6c92cecace30913b2d874a4c22b8d61ba1d71ea6039eca7ada870bf3f0c3c8fc12e46.6.15 – before 6.6.1586.7.3 – before 6.8
Linux Linux 6.8

References