--- id: CVE-2026-31678 title: 'kernel: openvswitch: defer tunnel netdev_put to RCU release (CVE-2026-31678)' summary: >- A flaw was found in the Linux kernel's Open vSwitch (OVS) component. A race condition can occur during the destruction of a network device (netdev) tunnel, where the `ovs_netdev_tunnel_destroy()` function may attempt to release a device re… severity: high cvss: 7.8 cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H' cvssSource: vendor cwe: CWE-367 vendor: Red Hat product: Red Hat Enterprise Linux BaseOS (v. 10) affected: - enterprise_linux 7 - enterprise_linux 9 - 10base_smtv - enterprise_linux_appstream_v_10 - enterprise_linux_appstream_v_9 - enterprise_linux_baseos_v_10 - enterprise_linux_baseos_v_8 - enterprise_linux_baseos_v_9 - enterprise_linux_codeready_linux_builder_v_10 - enterprise_linux_crb_v_8 - enterprise_linux_codeready_linux_builder_v_9 - enterprise_linux_hidden_v_10 - enterprise_linux_real_time_for_nfv_v_10 - enterprise_linux_nfv_v_8 - enterprise_linux_real_time_for_nfv_v_9 - enterprise_linux_real_time_v_10 - enterprise_linux_rt_v_8 - enterprise_linux_real_time_v_9 patched: - 10base_smtv - enterprise_linux_appstream_v_10 - enterprise_linux_appstream_v_9 - enterprise_linux_baseos_v_10 - enterprise_linux_baseos_v_8 - enterprise_linux_baseos_v_9 - enterprise_linux_codeready_linux_builder_v_10 - enterprise_linux_crb_v_8 - enterprise_linux_codeready_linux_builder_v_9 - enterprise_linux_hidden_v_10 - enterprise_linux_real_time_for_nfv_v_10 - enterprise_linux_nfv_v_8 - enterprise_linux_real_time_for_nfv_v_9 - enterprise_linux_real_time_v_10 - enterprise_linux_rt_v_8 - enterprise_linux_real_time_v_9 published: '2026-04-25' updated: '2026-10-20' sourceUpdated: '2026-10-20T23:01:47+00:00' source: CSAF sourceUrl: 'https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-31678.json' references: - url: >- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-31678.json - url: 'https://access.redhat.com/security/cve/CVE-2026-31678' - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2461761' - url: 'https://www.cve.org/CVERecord?id=CVE-2026-31678' - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-31678' - url: >- https://lore.kernel.org/linux-cve-announce/2026042544-CVE-2026-31678-79f5@gregkh/T - url: 'https://access.redhat.com/errata/RHSA-2026:85321' - url: 'https://access.redhat.com/errata/RHSA-2026:86033' - url: 'https://access.redhat.com/errata/RHSA-2026:82807' - url: 'https://access.redhat.com/errata/RHSA-2026:82806' - url: 'https://git.kernel.org/stable/c/9d56aced21fb9c104e8a3f3be9b21fbafe448ffc' - url: 'https://git.kernel.org/stable/c/42f0d3d81209654c08ffdde5a34b9b92d2645896' - url: 'https://git.kernel.org/stable/c/bbe7bd722bfaea36aab3da6cc60fb4a05c644643' - url: 'https://git.kernel.org/stable/c/98b726ab5e2a4811e27c28e4d041f75bba147eab' - url: 'https://git.kernel.org/stable/c/b8c56a3fc5d879c0928f207a756b0f067f06c6a8' - url: 'https://git.kernel.org/stable/c/6931d21f87bc6d657f145798fad0bf077b82486c' tags: - csaf - vex - red-hat - cve.org epss: 0.00132 epssPercentile: 0.02743 ssvc: exploitation: none automatable: 'no' technicalImpact: total timestamp: '2026-10-16T15:12:17.787623Z' ingestedAt: '2026-10-16T17:24:46.670Z' --- ## Overview A flaw was found in the Linux kernel's Open vSwitch (OVS) component. A race condition can occur during the destruction of a network device (netdev) tunnel, where the `ovs_netdev_tunnel_destroy()` function may attempt to release a device reference while other parts of the system are still actively using it. This timing issue, or race condition, could lead to system instability or a denial of service (DoS) due to improper resource handling. ## Vendor advisories - **RHSA-2026:85321** · Red Hat · fixed in: 10Base-SMTV, Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux BaseOS (v. 10), Red Hat Enterprise Linux CodeReady Linux Builder (v. 10), Red Hat Enterprise Linux Hidden (v. 10), Red Hat Enterprise Linux Real Time for NFV (v. 10), … · released 2026-10-19 · [advisory](https://access.redhat.com/errata/RHSA-2026:85321) - **RHSA-2026:86033** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 9), Red Hat Enterprise Linux BaseOS (v. 9), Red Hat Enterprise Linux CodeReady Linux Builder (v. 9), Red Hat Enterprise Linux Real Time for NFV (v. 9), Red Hat Enterprise Linux Real Time (v. 9) · released 2026-10-20 · [advisory](https://access.redhat.com/errata/RHSA-2026:86033) - **RHSA-2026:82807** · Red Hat · fixed in: Red Hat Enterprise Linux BaseOS (v. 8), Red Hat Enterprise Linux CRB (v. 8) · released 2026-10-14 · [advisory](https://access.redhat.com/errata/RHSA-2026:82807) - **RHSA-2026:82806** · Red Hat · fixed in: Red Hat Enterprise Linux NFV (v. 8), Red Hat Enterprise Linux RT (v. 8) · released 2026-10-14 · [advisory](https://access.redhat.com/errata/RHSA-2026:82806) - **Red Hat VEX** · Important · affected: Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 9 · no fix planned: Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 9 · updated 2026-10-20 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-31678.json) **kernel: openvswitch: defer tunnel netdev_put to RCU release** — rated Important by Red Hat. Released 2026-04-25, updated 2026-10-20. Affected: - Red Hat Enterprise Linux 7 - Red Hat Enterprise Linux 9 Fixed: - 10Base-SMTV - Red Hat Enterprise Linux AppStream (v. 10) - Red Hat Enterprise Linux AppStream (v. 9) - Red Hat Enterprise Linux BaseOS (v. 10) - Red Hat Enterprise Linux BaseOS (v. 8) - Red Hat Enterprise Linux BaseOS (v. 9) - Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) - Red Hat Enterprise Linux CRB (v. 8) - Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) - Red Hat Enterprise Linux Hidden (v. 10) - Red Hat Enterprise Linux Real Time for NFV (v. 10) - Red Hat Enterprise Linux NFV (v. 8) - Red Hat Enterprise Linux Real Time for NFV (v. 9) - Red Hat Enterprise Linux Real Time (v. 10) - Red Hat Enterprise Linux RT (v. 8) - Red Hat Enterprise Linux Real Time (v. 9) No fix planned: - Red Hat Enterprise Linux 7 - Red Hat Enterprise Linux 9 Not affected: - Red Hat Enterprise Linux 6 ## Remediation For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 The system must be rebooted for this update to take effect. Red Hat recommends treating all kernel errata as security-relevant. Given the kernel's fundamental role, any bug has a higher chance of impacting system security, even if that impact only becomes clear after a fix is published. Therefore, Red Hat prioritizes delivering fixes that improve our customers' overall security posture. Because of this proactive approach, a patch may be associa… https://access.redhat.com/errata/RHSA-2026:85321 For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 The system must be rebooted for this update to take effect. Red Hat recommends treating all kernel errata as security-relevant. Given the kernel's fundamental role, any bug has a higher chance of impacting system security, even if that impact only becomes clear after a fix is published. Therefore, Red Hat prioritizes delivering fixes that improve our customers' overall security posture. Because of this proactive approach, a patch may be associa… https://access.redhat.com/errata/RHSA-2026:86033 For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 The system must be rebooted for this update to take effect. Red Hat recommends treating all kernel errata as security-relevant. Given the kernel's fundamental role, any bug has a higher chance of impacting system security, even if that impact only becomes clear after a fix is published. Therefore, Red Hat prioritizes delivering fixes that improve our customers' overall security posture. Because of this proactive approach, a patch may be associa… https://access.redhat.com/errata/RHSA-2026:82807 Workarounds / mitigations: - To mitigate this issue, prevent the openvswitch module from being loaded. See https://access.redhat.com/solutions/41278 for instructions.