CVE-2026-72086: Linux Vulnerability

Description

In the Linux kernel, the following vulnerability has been resolved: scsi: xen: scsiback: Free the command tag on the TMR submit-failure path scsiback_device_action() obtains a command tag in scsiback_get_pend_req() and submits a task-management request with target_submit_tmr(). When target_submit_tmr() fails it returns < 0 and scsiback jumps to the err: label, which sends a response but frees nothing, leaking the tag. Impact: a pvSCSI guest can leak the command tags of a LUN's session, stopping the LUN, by issuing VSCSIIF_ACT_SCSI_ABORT or RESET requests whenever target_submit_tmr() fails. transport_generic_free_cmd() cannot be used here. By the time target_submit_tmr() returns an error it has already run __target_init_cmd() (so se_cmd->cmd_kref is one, not zero), and on its target_get_sess_cmd() error path it has freed se_cmd->se_tmr_req via core_tmr_release_req() while leaving SCF_SCSI_TMR_CDB set and the pointer dangling. Letting the command release run target_free_cmd_mem() would then double-free se_tmr_req. Use the same helper, which returns just the tag, on this path too.

Metrics

EPSS Probability

0.21%

10.9th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

Vendor	Product	Versions
Linux	Linux	>= 2dbcdf33dbf61f44b29adb52338282c3d7840d0e, < 4567ce79fe2f84c3dcc3a91b22a377cf482d33ad; >= 2dbcdf33dbf61f44b29adb52338282c3d7840d0e, < 6c01f0439098f00a64b246dc27479602201382f7; >= 2dbcdf33dbf61f44b29adb52338282c3d7840d0e, < 18d4f86816592586b38513543b5e1f9553bc271f; >= 2dbcdf33dbf61f44b29adb52338282c3d7840d0e, < fbc1bdede66d0f2cde83b75d6524ce1a815bb69f; >= 2dbcdf33dbf61f44b29adb52338282c3d7840d0e, < 255fb7b0cdc947b1c01929c7f133281342a3a6b5; >= 2dbcdf33dbf61f44b29adb52338282c3d7840d0e, < 1357fb32d42ad8da193e6da285f09e6452feabda; >= 2dbcdf33dbf61f44b29adb52338282c3d7840d0e, < 66aefc277ebb796ec285d550305535dc3fc0179f
Linux	Linux	4.6

References

Timeline

Published: Aug 15, 2026
Last Modified: Aug 17, 2026
Status: Received

Frequently Asked Questions

What is CVE-2026-72086?

In the Linux kernel, the following vulnerability has been resolved: scsi: xen: scsiback: Free the command tag on the TMR submit-failure path scsiback_device_action() obtains a command tag in scsiback_get_pend_req() and submits a task-management request with target_submit_tmr(). When target_submit_tmr() fails it returns < 0 and scsiback jumps to the err: label, which sends a response but frees nothing, leaking the tag. Impact: a pvSCSI guest can leak the command tags of a LUN's session, stopping the LUN, by issuing VSCSIIF_ACT_SCSI_ABORT or RESET requests whenever target_submit_tmr() fails. transport_generic_free_cmd() cannot be used here. By the time target_submit_tmr() returns an error it has already run __target_init_cmd() (so se_cmd->cmd_kref is one, not zero), and on its target_get_sess_cmd() error path it has freed se_cmd->se_tmr_req via core_tmr_release_req() while leaving SCF_SCSI_TMR_CDB set and the pointer dangling. Letting the command release run target_free_cmd_mem() would then double-free se_tmr_req. Use the same helper, which returns just the tag, on this path too.

How severe is CVE-2026-72086?

Severity scoring for CVE-2026-72086 is pending analysis. The EPSS model estimates a 0.21% probability of exploitation in the next 30 days.

How do I fix CVE-2026-72086?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

How Strix Helps

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