Use-after-free in Linux kernel - CVE-2026-98773

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Main Vulnerability Database Vulnerabilities #VU157137

Use-after-free in Linux kernel - CVE-2026-98773

Published: October 22, 2026


Vulnerability identifier: #VU157137
CSH Severity: Low
CVSS v4: 5.7 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-98773
CWE-ID: CWE-416
Exploitation vector: Local access
Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a local user to cause a denial of service by potentially crashing the kernel.

The vulnerability exists due to a use-after-free in the Linux kernel USB CDC ACM driver when port shutdown overlaps with device disconnection. A local user can trigger concurrent port shutdown and device disconnection to cause resubmitted USB request blocks to access freed DMA buffers in acm_ctrl_irq() or acm_read_bulk_callback(), potentially crashing the kernel.

The described USB request resubmission occurs when the ALWAYS_POLL_CTRL quirk is set.


Affected software

Linux kernel
SUSE Linux Micro
SUSE Linux Micro Extras
kernel-default
kernel-64kb
kernel-64kb-debugsource
kernel-64kb-devel
kernel-default-devel
kernel-syms
kernel-obs-build
kernel-obs-build-debugsource
kernel-default-debugsource
kernel-default-devel-debuginfo

How to mitigate CVE-2026-98773

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
kernel-default - update to 6.4.0-159998.55.1
kernel-64kb - update to 6.4.0-159998.55.1
kernel-64kb-debugsource - update to 6.4.0-159998.55.1
kernel-64kb-devel - update to 6.4.0-159998.55.1
kernel-default-devel - update to 6.4.0-159998.55.1
kernel-syms - update to 6.4.0-159998.55.1
kernel-obs-build - update to 6.4.0-159998.55.1
kernel-obs-build-debugsource - update to 6.4.0-159998.55.1
kernel-default-debugsource - update to 6.4.0-159998.55.1
kernel-default-devel-debuginfo - update to 6.4.0-159998.55.1

External References

Related Security Bulletins