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VulnerabilityPublished Updated

CVE-2026-72085: Linux kernel · Use After Free

Affects Linux kernelSource CVE Database V5

0

Not known to be exploited · CVSS 9.3 Critical · fixed in fcd64d4d97af5d9736f31040f8ed8cd4c17e4c45 : patch Linux kernel as a priority.

Data as of 26 Oct 2026, 17:30 UTC

CVSS 3.1 base score
9.3Critical
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.1% chance of exploitation in 30 days – higher than 7% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CISA SSVC
Exploitation
No evidence of active exploitation and no public proof of concept
Automatable
Attackers cannot reliably automate steps 1–4 of the kill chain
Technical impact
Total control over the software or total information disclosure

CISA SSVC assessment, 2026-10-16.

Patch
Available – fixed in fcd64d4d97af5d9736f31040f8ed8cd4c17e4c45, fa588f28401102652068c4cc75e135507f4b5106, f1516c56ac540da1769f264c3cfefe4499548a5d +4
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 15 Aug 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

ProductAffectedFixed in
LinuxLinuxAffected
  • ≥ 2dbcdf33dbf61f44b29adb52338282c3d7840d0e, < fcd64d4d97af5d9736f31040f8ed8cd4c17e4c45
Fixed in
  • fcd64d4d97af5d9736f31040f8ed8cd4c17e4c45
LinuxLinuxAffected
  • ≥ 2dbcdf33dbf61f44b29adb52338282c3d7840d0e, < fa588f28401102652068c4cc75e135507f4b5106
Fixed in
  • fa588f28401102652068c4cc75e135507f4b5106
LinuxLinuxAffected
  • ≥ 2dbcdf33dbf61f44b29adb52338282c3d7840d0e, < f1516c56ac540da1769f264c3cfefe4499548a5d
Fixed in
  • f1516c56ac540da1769f264c3cfefe4499548a5d
LinuxLinuxAffected
  • ≥ 2dbcdf33dbf61f44b29adb52338282c3d7840d0e, < ca978f8a93d4d36841839bf2847d29b88c2591d6
Fixed in
  • ca978f8a93d4d36841839bf2847d29b88c2591d6
LinuxLinuxAffected
  • ≥ 2dbcdf33dbf61f44b29adb52338282c3d7840d0e, < a13b789497a7fdd27d4d63f5c69d23db706ef0fe
Fixed in
  • a13b789497a7fdd27d4d63f5c69d23db706ef0fe
LinuxLinuxAffected
  • ≥ 2dbcdf33dbf61f44b29adb52338282c3d7840d0e, < 9c0f6894982b1f13bda220707497b25ac9c95bdb
Fixed in
  • 9c0f6894982b1f13bda220707497b25ac9c95bdb

Description

In the Linux kernel, the following vulnerability has been resolved: scsi: xen: scsiback: Free unsubmitted command instead of double-putting it scsiback_get_pend_req() obtains a command tag and returns a vscsibk_pend whose embedded se_cmd has only been memset to 0, so its cmd_kref is 0; the se_cmd is initialised (kref_init() via target_init_cmd()) only later, in scsiback_cmd_exec(), on the successful VSCSIIF_ACT_SCSI_CDB path. The two error paths in scsiback_do_cmd_fn() taken before the command is submitted -- a failed scsiback_gnttab_data_map() and an unknown ring_req.act -- call transport_generic_free_cmd(&pending_req->se_cmd, 0), which kref_put()s a refcount of 0. That underflows it ("refcount_t: underflow; use-after-free") and, as the release function is not run, leaks the command tag. Impact: a pvSCSI guest can leak every command tag of a LUN's session, stopping the LUN, by submitting requests with a bad grant reference or an unknown request type; under panic_on_warn the refcount underflow panics the host. Add a helper that just returns the tag with target_free_tag() and sends the error response. It frees the tag while the v2p reference still pins the session, and snapshots the response fields beforehand because freeing the tag can let another ring reuse the pending_req slot.

References

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