In the Linux kernel, the following vulnerability has been resolved: locking/rtmutex: Skip remove_waiter() when waiter is not enqueued syzbot triggered the following splat in remove_waiter() via FUTEX_CMP_REQUEUE_PI: KASAN: null-ptr-deref in range [0x0000000000000a88-0x0000000000000a8f] class_raw_spinlock_constructor remove_waiter+0x159/0x1200 kernel/locking/rtmutex.c:1561 rt_mutex_start_proxy_lock+0x103/0x120 futex_requeue+0x10e4/0x20d0 __x64_sys_futex+0x34f/0x4d0 task_blocks_on_rt_mutex() does not arm the waiter upon deadlock detection, leaving waiter->task nil, where 3bfdc63936dd ("rtmutex: Use waiter::task instead of current in remove_waiter()") made this fatal. Furthermore, rt_mutex_start_proxy_lock() should not be calling into remove_waiter() upon a successfully grabbing the rtmutex. 1a1fb985f2e2 ("futex: Handle early deadlock return correctly"), moved the remove_waiter() out of __rt_mutex_start_proxy_lock() (where 'ret' was only ever 0 or < 0) into the wrapper. Tighten this check to account for try_to_take_rt_mutex().

It is, therefore, affected by a vulnerability as referenced in the ALAS2023-2026-1987 advisory.

    In the Linux kernel, the following vulnerability has been resolved:

    locking/rtmutex: Skip remove_waiter() when waiter is not enqueued (CVE-2026-53163)

Tenable has extracted the preceding description block directly from the tested product security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote Debian 12 host has packages installed that are affected by multiple vulnerabilities as referenced in the dla-4688 advisory.

    -------------------------------------------------------------------------     Debian LTS Advisory DLA-4688-1                debian-lts@lists.debian.org     https://www.debian.org/lts/security/                        Ben Hutchings     July 18, 2026                                 https://wiki.debian.org/LTS
    -------------------------------------------------------------------------

    Package        : linux     Version        : 6.1.177-1     CVE ID         : CVE-2025-23131 CVE-2026-23272 CVE-2026-23278 CVE-2026-23302                      CVE-2026-31451 CVE-2026-46252 CVE-2026-52928 CVE-2026-53138                      CVE-2026-53139 CVE-2026-53157 CVE-2026-53158 CVE-2026-53163                      CVE-2026-53167 CVE-2026-53325 CVE-2026-53327 CVE-2026-53359                      CVE-2026-53362 CVE-2026-53366     Debian Bug     : 1130365

    Several vulnerabilities have been discovered in the Linux kernel that     may lead to a privilege escalation, denial of service or information     leaks.

    For Debian 12 bookworm, these problems have been fixed in version     6.1.177-1.  This version additionally updates the Microsoft Azure     Network Adapter (mana) driver, and includes many more bug fixes from     stable update 6.1.177.

    We recommend that you upgrade your linux packages.

    For the detailed security status of linux please refer to     its security tracker page at:
    https://security-tracker.debian.org/tracker/linux

    Further information about Debian LTS security advisories, how to apply     these updates to your system and frequently asked questions can be     found at: https://wiki.debian.org/LTS     Attachment:
    signature.asc     Description: PGP signature

Tenable has extracted the preceding description block directly from the Debian security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote Debian 13 host has packages installed that are affected by multiple vulnerabilities as referenced in the dsa-6381 advisory.

    - -------------------------------------------------------------------------     Debian Security Advisory DSA-6381-1                   security@debian.org     https://www.debian.org/security/                     Salvatore Bonaccorso     July 05, 2026                         https://www.debian.org/security/faq
    - -------------------------------------------------------------------------

    Package        : linux     CVE ID         : CVE-2025-23131 CVE-2026-31419 CVE-2026-31732 CVE-2026-43010                      CVE-2026-43216 CVE-2026-43355 CVE-2026-46054 CVE-2026-46242                      CVE-2026-46252 CVE-2026-52975 CVE-2026-53070 CVE-2026-53101                      CVE-2026-53139 CVE-2026-53142 CVE-2026-53151 CVE-2026-53157                      CVE-2026-53163 CVE-2026-53167 CVE-2026-53179 CVE-2026-53325                      CVE-2026-53327 CVE-2026-53341 CVE-2026-53359 CVE-2026-53361                      CVE-2026-53362     Debian Bug     : 1136179 1139686

    Several vulnerabilities have been discovered in the Linux kernel that     may lead to a privilege escalation, denial of service or information     leaks.

    For the stable distribution (trixie), these problems have been fixed in     version 6.12.95-1.

    We recommend that you upgrade your linux packages.

    For the detailed security status of linux please refer to its security     tracker page at:
    https://security-tracker.debian.org/tracker/linux

    Further information about Debian Security Advisories, how to apply     these updates to your system and frequently asked questions can be     found at: https://www.debian.org/security/

    Mailing list: debian-security-announce@lists.debian.org

Tenable has extracted the preceding description block directly from the Debian security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - locking/rtmutex: Skip remove_waiter() when waiter is not enqueued syzbot triggered the following splat in     remove_waiter() via FUTEX_CMP_REQUEUE_PI: KASAN: null-ptr-deref in range     [0x0000000000000a88-0x0000000000000a8f] class_raw_spinlock_constructor remove_waiter+0x159/0x1200     kernel/locking/rtmutex.c:1561 rt_mutex_start_proxy_lock+0x103/0x120 futex_requeue+0x10e4/0x20d0
    __x64_sys_futex+0x34f/0x4d0 task_blocks_on_rt_mutex() does not arm the waiter upon deadlock detection,     leaving waiter->task nil, where 3bfdc63936dd (rtmutex: Use waiter::task instead of current in     remove_waiter()) made this fatal. Furthermore, rt_mutex_start_proxy_lock() should not be calling into     remove_waiter() upon a successfully grabbing the rtmutex. 1a1fb985f2e2 (futex: Handle early deadlock     return correctly), moved the remove_waiter() out of __rt_mutex_start_proxy_lock() (where 'ret' was only     ever 0 or < 0) into the wrapper. Tighten this check to account for try_to_take_rt_mutex().
    (CVE-2026-53163)

Note that Nessus relies on the presence of the package as reported by the vendor.

ID	Name	Product	Family	Severity
328494	Amazon Linux 2023 : bpftool6.12, kernel6.12, kernel6.12-devel (ALAS2023-2026-1987)	Nessus	Amazon Linux Local Security Checks	medium
327788	Debian dla-4688 : ata-modules-6.1.0-48-armmp-di - security update	Nessus	Debian Local Security Checks	high
327383	Amazon Linux 2023 : bpftool6.18, kernel6.18, kernel6.18-devel (ALAS2023-2026-1925)	Nessus	Amazon Linux Local Security Checks	high
325146	Debian dsa-6381 : ata-modules-6.12.90+deb13-armmp-di - security update	Nessus	Debian Local Security Checks	high
323419	Linux Distros Unpatched Vulnerability : CVE-2026-53163	Nessus	Misc.	medium

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