SB2026110922 - Debian update for linux
Published: November 9, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 3 vulnerabilities.
1) Use-after-free (CVE-ID: CVE-2026-100080)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 5.7 [CVSS:4.0/AV:L/AC:L/AT:P/PR:H/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a local privileged user to cause a denial of service or potentially disclose sensitive information.
The vulnerability exists due to a use-after-free in the Linux kernel xen-netback driver when queue teardown following a frontend connection error frees statistics data without synchronizing RCU readers. A local privileged user can supply invalid Xenstore data from a guest to trigger this error path while statistics are being read through sysfs, potentially causing a kernel crash or exposing information from freed or reused memory.
2) Use-after-free (CVE-ID: CVE-2026-100081)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 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]
The vulnerability allows a local user to potentially cause a denial of service through access to freed kernel memory.
The vulnerability exists due to use-after-free in the Linux kernel xen-netback multicast address list handling when interface disconnection overlaps with transmit or receive processing. A local user can trigger concurrent network processing and interface disconnection to potentially cause active processing to access freed list entries and crash the kernel.
3) Use-after-free (CVE-ID: CVE-2026-100082)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 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]
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to use-after-free in the Linux kernel xen-blkback driver when reading I/O statistics via sysfs concurrently with frontend device teardown. A local user can read statistics while the underlying data is being freed to potentially trigger a kernel crash and cause a denial of service.
Remediation
Install update from vendor's website.