Vulnerability · CVE-2026-99156

scsi: st: Fix use-after-free race between st_remove() and st_open()

Published Oct 28, 2026 · catalog updated Nov 1, 2026 · BSI

Last checked Nov 4, 2026. A connected source was read within the last 7 days.

Check if you run it

No confirmed exploitation is on record for CVE-2026-99156. EPSS is 0.13%. Act only if a listed version of BSI is installed.

Gaps on this record

No vendor fix or required action is stored. Compare the linked advisory before you change production.

Severity: High7.8
Known exploitation: Not in CISA/VulnCheck KEV
EPSS: 0.13%
Remediation: Advisory link
Affected products: Debian:12 linux · Debian:13 linux · Debian:14 linux · Linux Kernel

In the Linux kernel, the following vulnerability has been resolved: scsi: st: Fix use-after-free race between st_remove() and st_open() st_remove() drops the probe reference on the scsi_tape with kref_put() and only afterwards removes its index from st_index_idr. If that was the last reference, scsi_tape_release() frees the structure while it is still published in the idr. scsi_tape_get(), called from st_open(), looks up the tape in st_index_idr and takes a reference under st_ref_mutex and st_index_lock. remove_cdevs() does not wait for opens that are already past chrdev_open(), so an open that is blocked on st_ref_mutex while st_remove() holds it can take the mutex as soon as st_remove() drops it, find the freed tpnt in the idr and call kref_get() on it: BUG: KASAN: slab-use-after-free in st_open Write of size 4 ... st_open (drivers/scsi/st.c:254 drivers/scsi/st.c:1291) chrdev_open ... Freed by task ...: kfree st_remove (drivers/scsi/st.c:4512) Remove the index from the idr before dropping the reference, all under st_ref_mutex. A concurrent scsi_tape_get() now either runs first and holds a valid reference that keeps the tape alive, or runs afterwards and finds nothing, so st_open() fails with -ENXIO. This restores the ordering st_remove() had before the conversion to st_index_idr, where the tape was unpublished from scsi_tapes[] before the final kref_put().

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

Debian:12 linux6.1.106-1, 6.1.106-2, 6.1.106-3
Debian:13 linux6.12.100-1, 6.12.101-1, 6.12.105-1
Debian:14 linux6.12.100-1, 6.12.101-1, 6.12.105-1
Linux Kernel3.7.0 → 5.10.273; 5.11.0 → 5.15.224; 5.16.0 → 6.1.191

How to fix CVE-2026-99156

Upgrade
CVE-2026-99156 lists a fix boundary at 5.10.273. Compare the installed build with that boundary before you change production.
Version check
Seen in 6.1.106-1 · 9 other packages on the advisory
Advisory
Open the bsi record and follow its fix.
Official advisories

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-99156. EPSS is 0.13%. Act only if a listed version of BSI is installed.

Which versions are affected?

Compare what you have installed with Kernel 3.7.0 → 5.10.273; 5.11.0 → 5.15.224; 5.16.0 → 6.1.191. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

No weakness class is stored. EPSS 0.13%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Technology hubs

Debian security

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

Oct 29, 2026 · BSI CERT-Bund
Detected
CVE-2026-99156 is listed by Linux Kernel: Mehrere Schwachstellen ermöglichen nicht spezifizierten Angriff.
Nov 1, 2026 · OpenSSF OSV / OSV Scanner
Fix available
Kernel fixed in 5.10.273; Kernel fixed in 5.15.224; Kernel fixed in 6.1.191; Kernel fixed in 6.6.161
Nov 1, 2026 · OpenSSF OSV / OSV Scanner
Fix available
Kernel fixed in 5.10.273; 5.11.0
Nov 1, 2026 · OpenSSF OSV / OSV Scanner
Updated
In the Linux kernel, the following vulnerability has been resolved: scsi: st: Fix use-after-free race between st_remove() and st_open() st_remove() drops the probe reference on the scsi_tape with kref_put() and only afterwards removes its index from st_index_idr. If that was the last reference, scsi_tape_release() frees the structure while it is still published in the idr. scsi_tape_get(), called
Nov 1, 2026 · Trivy Vulnerability DB
Updated
In the Linux kernel, the following vulnerability has been resolved: scsi: st: Fix use-after-free race between st_remove() and st_open() st_remove() drops the probe reference on the scsi_tape with kref_put() and only afterwards removes its index from st_index_idr. If that was the last reference, scsi_tape_release() frees the structure while it is still published in the idr. scsi_tape_get(), called

Sources

BSI CERT-BundGovernment advisoryCVE-2026-99156
Linux Kernel: Mehrere Schwachstellen ermöglichen nicht spezifizierten Angriff
wid.cert-bund.de
CVE.orgVulnerability recordCVE-2026-99156
Official CVE identifier
cve.org
FIRST EPSSExploitation probabilityCVE-2026-99156
30-day exploitation probability 0.13%
first.org
OpenSSF OSV / OSV ScannerPackage advisoryCVE-2026-99156
scsi: st: Fix use-after-free race between st_remove() and st_open()
osv.dev
Tenable CVE DatabaseVulnerability recordCVE-2026-99156
In the Linux kernel, the following vulnerability has been resolved: scsi: st: Fix use-after-free race between st_remove() and st_open() st_remove() drops the probe reference on the scsi_tape with kref_put() and only afterwards removes its index from st_index_idr. If that was the last reference, scsi_tape_release() frees the structure while it is still published in the idr. scsi_tape_get(), called
tenable.com
Trivy Vulnerability DBPackage advisoryDEBIAN-CVE-2026-99156
In the Linux kernel, the following vulnerability has been resolved: scsi: st: Fix use-after-free race between st_remove() and st_open() st_remove() drops the probe reference on the scsi_tape with kref_put() and only afterwards removes its index from st_index_idr. If that was the
osv.dev

References

Freshness

Last verified in this catalog Nov 4, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.

FIRST EPSSNov 4, 2026
Trivy Vulnerability DBNov 1, 2026
Tenable CVE DatabaseNov 1, 2026
OpenSSF OSV / OSV ScannerNov 1, 2026
CVE.orgOct 30, 2026
BSI CERT-BundOct 30, 2026

Priority score

24/100

Evidence confidence: High

A vendor or government advisory agrees with at least one other source.

Confirmed exploitation0/30
EPSS probability1/20
CVSS severity12/15
Public exploit0/10
Internet exposure6/10
Product prevalence5/5
Detection0/5
Threat research0/5

Decision signals

Four separate signals — do not infer one from another.

High

CVSS severity
7.8 v3.1
Technical impact. Separate from exploitation likelihood.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS probability
0.13% · p2.63%
Estimated probability of exploitation within 30 days (FIRST).
Known exploitation
No verified KEV listing
Evidence from CISA KEV or VulnCheck KEV only — not from EPSS alone.
Patch availability
Advisory link
A patch or advisory reference is linked. Open the original publisher for availability by product version.

Stacks

Debian Debian 12 Debian 13 Debian 14 Linux

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