In the Linux kernel, the following vulnerability has been resolved: serial: caif: hold tty->link reference in ldisc_open and ser_release A reproducer triggers a KASAN slab-use-after-free in pty_write_room() when caif_serial's TX path calls tty_write_room(). The faulting access is on tty->link->port. Hold an extra kref on tty->link for the lifetime of the caif_serial line discipline: get it in ldisc_open() and drop it in ser_release(), and also drop it on the ldisc_open() error path. With this change applied, the reproducer no longer triggers the UAF in my testing.

An update of the linux package has been released.

The remote Debian 11 host has packages installed that are affected by multiple vulnerabilities as referenced in the dla-4606 advisory.

    -------------------------------------------------------------------------     Debian LTS Advisory DLA-4606-1                debian-lts@lists.debian.org     https://www.debian.org/lts/security/                        Ben Hutchings     May 29, 2026                                  https://wiki.debian.org/LTS
    -------------------------------------------------------------------------

    Package        : linux     Version        : 5.10.257-1     CVE ID         : CVE-2024-56584 CVE-2025-39748 CVE-2025-39764 CVE-2025-40219                      CVE-2025-40261 CVE-2025-68206 CVE-2025-71274 CVE-2025-71292                      CVE-2025-71304 CVE-2026-23100 CVE-2026-23112 CVE-2026-23227                      CVE-2026-23242 CVE-2026-23243 CVE-2026-23245 CVE-2026-23253                      CVE-2026-23273 CVE-2026-23274 CVE-2026-23277 CVE-2026-23279                      CVE-2026-23281 CVE-2026-23286 CVE-2026-23289 CVE-2026-23290                      CVE-2026-23291 CVE-2026-23293 CVE-2026-23298 CVE-2026-23300                      CVE-2026-23303 CVE-2026-23304 CVE-2026-23307 CVE-2026-23312                      CVE-2026-23318 CVE-2026-23336 CVE-2026-23339 CVE-2026-23351                      CVE-2026-23352 CVE-2026-23356 CVE-2026-23357 CVE-2026-23362                      CVE-2026-23365 CVE-2026-23367 CVE-2026-23368 CVE-2026-23372                      CVE-2026-23379 CVE-2026-23381 CVE-2026-23382 CVE-2026-23388                      CVE-2026-23391 CVE-2026-23395 CVE-2026-23396 CVE-2026-23397                      CVE-2026-23398 CVE-2026-23420 CVE-2026-23434 CVE-2026-23439                      CVE-2026-23446 CVE-2026-23452 CVE-2026-23455 CVE-2026-23456                      CVE-2026-23457 CVE-2026-23458 CVE-2026-23460 CVE-2026-23462                      CVE-2026-23463 CVE-2026-23474 CVE-2026-31391 CVE-2026-31393                      CVE-2026-31396 CVE-2026-31399 CVE-2026-31400 CVE-2026-31402                      CVE-2026-31403 CVE-2026-31405 CVE-2026-31411 CVE-2026-31415                      CVE-2026-31416 CVE-2026-31417 CVE-2026-31418 CVE-2026-31421                      CVE-2026-31422 CVE-2026-31423 CVE-2026-31424 CVE-2026-31425                      CVE-2026-31427 CVE-2026-31428 CVE-2026-31447 CVE-2026-31450                      CVE-2026-31452 CVE-2026-31454 CVE-2026-31455 CVE-2026-31466                      CVE-2026-31469 CVE-2026-31473 CVE-2026-31485 CVE-2026-31494                      CVE-2026-31495 CVE-2026-31497 CVE-2026-31498 CVE-2026-31504                      CVE-2026-31507 CVE-2026-31508 CVE-2026-31509 CVE-2026-31510                      CVE-2026-31512 CVE-2026-31515 CVE-2026-31518 CVE-2026-31523                      CVE-2026-31524 CVE-2026-31545 CVE-2026-31546 CVE-2026-31550                      CVE-2026-31552 CVE-2026-31555 CVE-2026-31570 CVE-2026-31628                      CVE-2026-31649 CVE-2026-31651 CVE-2026-31658 CVE-2026-31659                      CVE-2026-31660 CVE-2026-31661 CVE-2026-31662 CVE-2026-31665                      CVE-2026-31667 CVE-2026-31668 CVE-2026-31670 CVE-2026-31671                      CVE-2026-31672 CVE-2026-31674 CVE-2026-31679 CVE-2026-31680                      CVE-2026-31682 CVE-2026-31683 CVE-2026-31720 CVE-2026-31721                      CVE-2026-31726 CVE-2026-31728 CVE-2026-31737 CVE-2026-31738                      CVE-2026-31747 CVE-2026-31748 CVE-2026-31749 CVE-2026-31751                      CVE-2026-31752 CVE-2026-31758 CVE-2026-31759 CVE-2026-31761                      CVE-2026-31762 CVE-2026-31763 CVE-2026-31770 CVE-2026-31773                      CVE-2026-31778 CVE-2026-31780 CVE-2026-31781 CVE-2026-31786                      CVE-2026-31787 CVE-2026-31788 CVE-2026-43011 CVE-2026-43014                      CVE-2026-43015 CVE-2026-43020 CVE-2026-43024 CVE-2026-43026                      CVE-2026-43027 CVE-2026-43028 CVE-2026-43030 CVE-2026-43032                      CVE-2026-43035 CVE-2026-43037 CVE-2026-43038 CVE-2026-43040                      CVE-2026-43041 CVE-2026-43043 CVE-2026-43047 CVE-2026-43050                      CVE-2026-43051 CVE-2026-43060 CVE-2026-43061 CVE-2026-43062                      CVE-2026-43066 CVE-2026-43068 CVE-2026-43069 CVE-2026-43077                      CVE-2026-43078 CVE-2026-43124 CVE-2026-43130 CVE-2026-43132                      CVE-2026-43134 CVE-2026-43135 CVE-2026-43136 CVE-2026-43139                      CVE-2026-43140 CVE-2026-43141 CVE-2026-43147 CVE-2026-43149                      CVE-2026-43152 CVE-2026-43156 CVE-2026-43158 CVE-2026-43159                      CVE-2026-43163 CVE-2026-43168 CVE-2026-43171 CVE-2026-43180                      CVE-2026-43183 CVE-2026-43184 CVE-2026-43187 CVE-2026-43190                      CVE-2026-43194 CVE-2026-43196 CVE-2026-43202 CVE-2026-43203                      CVE-2026-43206 CVE-2026-43207 CVE-2026-43209 CVE-2026-43211                      CVE-2026-43218 CVE-2026-43223 CVE-2026-43226 CVE-2026-43227                      CVE-2026-43230 CVE-2026-43231 CVE-2026-43232 CVE-2026-43233                      CVE-2026-43236 CVE-2026-43241 CVE-2026-43242 CVE-2026-43246                      CVE-2026-43251 CVE-2026-43255 CVE-2026-43257 CVE-2026-43261                      CVE-2026-43264 CVE-2026-43266 CVE-2026-43268 CVE-2026-43269                      CVE-2026-43270 CVE-2026-43273 CVE-2026-43277 CVE-2026-43283                      CVE-2026-43287 CVE-2026-43289 CVE-2026-43295 CVE-2026-43296                      CVE-2026-43314 CVE-2026-43316 CVE-2026-43327 CVE-2026-43328                      CVE-2026-43334 CVE-2026-43336 CVE-2026-43339 CVE-2026-43340                      CVE-2026-43342 CVE-2026-43343 CVE-2026-43355 CVE-2026-43357                      CVE-2026-43363 CVE-2026-43370 CVE-2026-43373 CVE-2026-43381                      CVE-2026-43382 CVE-2026-43383 CVE-2026-43386 CVE-2026-43387                      CVE-2026-43407 CVE-2026-43411 CVE-2026-43420 CVE-2026-43424                      CVE-2026-43425 CVE-2026-43426 CVE-2026-43427 CVE-2026-43428                      CVE-2026-43429 CVE-2026-43430 CVE-2026-43432 CVE-2026-43437                      CVE-2026-43439 CVE-2026-43445 CVE-2026-43449 CVE-2026-43450                      CVE-2026-43451 CVE-2026-43452 CVE-2026-43453 CVE-2026-43458                      CVE-2026-43459 CVE-2026-43466 CVE-2026-43472 CVE-2026-43475                      CVE-2026-43480 CVE-2026-43503 CVE-2026-45848 CVE-2026-45852                      CVE-2026-45856 CVE-2026-45857 CVE-2026-45860 CVE-2026-45862                      CVE-2026-45866 CVE-2026-45867 CVE-2026-45868 CVE-2026-45869                      CVE-2026-45870 CVE-2026-45871 CVE-2026-45873 CVE-2026-45875                      CVE-2026-45879 CVE-2026-45883 CVE-2026-45885 CVE-2026-45890                      CVE-2026-45899 CVE-2026-45904 CVE-2026-45912 CVE-2026-45914                      CVE-2026-45915 CVE-2026-45916 CVE-2026-45919 CVE-2026-45920                      CVE-2026-45923 CVE-2026-45936 CVE-2026-45941 CVE-2026-45948                      CVE-2026-45954 CVE-2026-45956 CVE-2026-45958 CVE-2026-45960                      CVE-2026-45964 CVE-2026-45965 CVE-2026-45968 CVE-2026-45970                      CVE-2026-45974 CVE-2026-45978 CVE-2026-45981 CVE-2026-45983                      CVE-2026-45984 CVE-2026-45985 CVE-2026-46028 CVE-2026-46174                      CVE-2026-46300

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

    For Debian 11 bullseye, these problems have been fixed in version     5.10.257-1.  This version additionally includes many more bug fixes     from stable updates 5.10.252-5.10.257.

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

  - serial: caif: hold tty->link reference in ldisc_open and ser_release A reproducer triggers a KASAN slab-     use-after-free in pty_write_room() when caif_serial's TX path calls tty_write_room(). The faulting access     is on tty->link->port. Hold an extra kref on tty->link for the lifetime of the caif_serial line     discipline: get it in ldisc_open() and drop it in ser_release(), and also drop it on the ldisc_open()     error path. With this change applied, the reproducer no longer triggers the UAF in my testing.
    (CVE-2026-43458)

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

ID	Name	Product	Family	Severity
329326	Photon OS 5.0: Linux PHSA-2026-5.0-0926	Nessus	PhotonOS Local Security Checks	high
329305	openSUSE 16: cluster-md-kmp-64kb / cluster-md-kmp-azure / cluster-md-kmp-default / etc (openSUSE-SU-2026:21388-1)	Nessus	SuSE Local Security Checks	high
321210	Photon OS 5.0: Linux PHSA-2026-5.0-0837	Nessus	PhotonOS Local Security Checks	high
318288	Debian dla-4606 : ata-modules-5.10.0-43-armmp-di - security update	Nessus	Debian Local Security Checks	critical
313507	Photon OS 5.0: Linux PHSA-2026-5.0-0842	Nessus	PhotonOS Local Security Checks	high
313372	Linux Distros Unpatched Vulnerability : CVE-2026-43458	Nessus	Misc.	high
310098	Photon OS 4.0: Linux PHSA-2026-4.0-1002	Nessus	PhotonOS Local Security Checks	high

Detections

Analytics

CVE-2026-43458

high

Tenable Plugins

high

high

high

critical

high

high

high