Linux Kernel up to 6.18.58/7.2.12 bsg ufshcd_advanced_rpmb_req_handler buffer overflow

CVSS Meta Temp Score
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CTI Interest Score
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7.8$0-$5k1.37

Summaryinfo

A vulnerability identified as very critical has been detected in Linux Kernel up to 6.18.58/7.2.12. This affects the function ufshcd_advanced_rpmb_req_handler of the component bsg. This manipulation causes buffer overflow. This vulnerability is handled as CVE-2026-99157. It is possible to launch the attack on the local host. There is not any exploit available. You should upgrade the affected component.

Detailsinfo

A vulnerability has been found in Linux Kernel up to 6.18.58/7.2.12 and classified as very critical. Affected by this vulnerability is the function ufshcd_advanced_rpmb_req_handler of the component bsg. The manipulation with an unknown input leads to a buffer overflow vulnerability. The CWE definition for the vulnerability is CWE-120. The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer, leading to a buffer overflow. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: scsi: bsg: Pass reply_len to bsg_setup_queue() to fit UFS ARPMB replies bsg-lib allocates a 96-byte (SCSI_SENSE_BUFFERSIZE) reply buffer per job, but struct ufs_rpmb_reply is 104 bytes: a 40-byte struct ufs_bsg_reply followed by a 64-byte EHS. When an Advanced RPMB command returns an EHS, ufshcd_advanced_rpmb_req_handler() copies it right after the 40-byte header and writes 8 bytes past the end of the buffer. Let each BSG transport pass its reply buffer size to bsg_setup_queue() and have ufs_bsg request sizeof(struct ufs_rpmb_reply), so the full reply reaches user space. Other transports keep SCSI_SENSE_BUFFERSIZE.

It is possible to read the advisory at git.kernel.org. This vulnerability is known as CVE-2026-99157 since 09/25/2026. The exploitation appears to be easy. Attacking locally is a requirement. The exploitation needs additional levels of successful authentication. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k 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 2effbe746452c108188f85a6951f2b0b65653840/7a755f6d47b811d3abd93c1642ce5e63894540b8/ec6b083915e8146e147314a5f4f1285d07b57bfc is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.2
VulDB Meta Temp Score: 7.8

VulDB Base Score: 8.2
VulDB Temp Score: 7.8
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

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

Exploitinginfo

Class: Buffer overflow
CWE: CWE-120 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: No

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: 2effbe746452c108188f85a6951f2b0b65653840/7a755f6d47b811d3abd93c1642ce5e63894540b8/ec6b083915e8146e147314a5f4f1285d07b57bfc

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-2026-99157 (🔒)
GCVE (CVE): GCVE-0-2026-99157
GCVE (VulDB): GCVE-100-427891

Entryinfo

Created: 10/28/2026 12:43
Changes: 10/28/2026 12:43 (59)
Complete: 🔍
Cache ID: 216::103

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