Linux Kernel up to 6.16.5 mchp_coreqspi_setup_clock privilege escalation

CVSS Meta Temp Score
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CTI Interest Score
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5.4$0-$5k0.00

Summaryinfo

A vulnerability described as critical has been identified in Linux Kernel up to 6.16.5. Affected by this issue is the function mchp_coreqspi_setup_clock. Such manipulation leads to an unknown weakness. This vulnerability is uniquely identified as CVE-2025-39921. No exploit exists. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.16.5. It has been rated as critical. The impact remains unknown. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: spi: microchip-core-qspi: stop checking viability of op->max_freq in supports_op callback In commit 13529647743d9 ("spi: microchip-core-qspi: Support per spi-mem operation frequency switches") the logic for checking the viability of op->max_freq in mchp_coreqspi_setup_clock() was copied into mchp_coreqspi_supports_op(). Unfortunately, op->max_freq is not valid when this function is called during probe but is instead zero. Accordingly, baud_rate_val is calculated to be INT_MAX due to division by zero, causing probe of the attached memory device to fail. Seemingly spi-microchip-core-qspi was the only driver that had such a modification made to its supports_op callback when the per_op_freq capability was added, so just remove it to restore prior functionality.

The advisory is shared for download at git.kernel.org. This vulnerability is handled as CVE-2025-39921 since 04/16/2025. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 01/08/2026).

The vulnerability scanner Nessus provides a plugin with the ID 269672 (Linux Distros Unpatched Vulnerability : CVE-2025-39921), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.16.6 eliminates this vulnerability. Applying the patch ac8a13f35d5b8996582b3f97b924838a5c570c18/89e7353f522f5cf70cb48c01ce2dcdcb275b8022 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (269672), EUVD (EUVD-2025-31830) and CERT Bund (WID-SEC-2025-2170). Once again VulDB remains the best source for vulnerability data.

Affected

  • Debian Linux
  • Amazon Linux 2
  • Red Hat Enterprise Linux
  • Ubuntu Linux
  • SUSE Linux
  • Oracle Linux
  • SUSE openSUSE
  • RESF Rocky Linux
  • Open Source Linux Kernel
  • Dell Secure Connect Gateway

Productinfo

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Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.5
VulDB Meta Temp Score: 5.4

VulDB Base Score: 5.5
VulDB Temp Score: 5.3
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 5.5
NVD Vector: 🔒

CVSSv2info

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

Exploitinginfo

Class: Privilege escalation
CWE: Unknown
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 269672
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2025-39921

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.16.6
Patch: ac8a13f35d5b8996582b3f97b924838a5c570c18/89e7353f522f5cf70cb48c01ce2dcdcb275b8022

Timelineinfo

04/16/2025 CVE reserved
10/01/2025 +168 days Advisory disclosed
10/01/2025 +0 days VulDB entry created
01/08/2026 +99 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2025-39921 (🔒)
GCVE (CVE): GCVE-0-2025-39921
GCVE (VulDB): GCVE-100-326492
EUVD: 🔒
CERT Bund: WID-SEC-2025-2170 - Linux Kernel: Mehrere Schwachstellen

Entryinfo

Created: 10/01/2025 10:25
Updated: 01/08/2026 19:33
Changes: 10/01/2025 10:25 (57), 10/01/2025 13:35 (1), 10/02/2025 01:42 (7), 10/10/2025 00:13 (2), 11/25/2025 06:18 (1), 12/01/2025 18:54 (1), 12/12/2025 02:26 (10), 01/08/2026 19:33 (1)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

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