Linux Kernel up to 6.18.58/7.2.12 scsi drivers/scsi/st.c st_remove/st_open use after free

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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9.5$5k-$25k0.66+

Summaryinfo

A vulnerability described as very critical has been identified in Linux Kernel up to 6.18.58/7.2.12. Impacted is the function st_remove/st_open of the file drivers/scsi/st.c of the component scsi. Executing a manipulation can lead to use after free. The identification of this vulnerability is CVE-2026-99156. The attack may be launched remotely. There is no exploit available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.18.58/7.2.12. It has been declared as very critical. This vulnerability affects the function st_remove/st_open of the file drivers/scsi/st.c of the component scsi. The manipulation with an unknown input leads to a use after free vulnerability. The CWE definition for the vulnerability is CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

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().

The advisory is available at git.kernel.org. This vulnerability was named CVE-2026-99156 since 09/25/2026. The exploitation appears to be easy. The attack can be initiated remotely. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $5k-$25k at the moment (estimation calculated on 10/28/2026).

Upgrading to version 6.18.59 or 7.2.13 eliminates this vulnerability. Applying the patch a1647b653549ff29f0422a63eabf329b842f3822/18a0e3733ce38718688e813e5e2d1106bd4830e5/71caf7f84bd62a4bf91cc95abd2de690afb8d15f is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 9.9
VulDB Meta Temp Score: 9.5

VulDB Base Score: 9.9
VulDB Temp Score: 9.5
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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💳💳💳💳💳💳
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Use after free
CWE: CWE-416 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.18.59/7.2.13
Patch: a1647b653549ff29f0422a63eabf329b842f3822/18a0e3733ce38718688e813e5e2d1106bd4830e5/71caf7f84bd62a4bf91cc95abd2de690afb8d15f

Timelineinfo

09/25/2026 CVE reserved
10/28/2026 +33 days Advisory disclosed
10/28/2026 +0 days VulDB entry created
10/28/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-99156 (🔒)
GCVE (CVE): GCVE-0-2026-99156
GCVE (VulDB): GCVE-100-427894

Entryinfo

Created: 10/28/2026 12:43
Changes: 10/28/2026 12:43 (60)
Complete: 🔍
Cache ID: 216::103

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