Linux Kernel up to 6.16.1 fbdev vc_do_resize out-of-bounds write

CVSS Meta Temp Score
CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.
Current Exploit Price (≈)
Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.
CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
7.7$0-$5k0.00

Summaryinfo

A vulnerability classified as critical has been found in Linux Kernel up to 6.16.1. The affected element is the function vc_do_resize of the component fbdev. The manipulation leads to out-of-bounds write. This vulnerability is traded as CVE-2025-38685. There is no exploit available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.16.1. It has been rated as critical. This issue affects the function vc_do_resize of the component fbdev. The manipulation with an unknown input leads to a out-of-bounds write vulnerability. Using CWE to declare the problem leads to CWE-787. The product writes data past the end, or before the beginning, of the intended buffer. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: fbdev: Fix vmalloc out-of-bounds write in fast_imageblit This issue triggers when a userspace program does an ioctl FBIOPUT_CON2FBMAP by passing console number and frame buffer number. Ideally this maps console to frame buffer and updates the screen if console is visible. As part of mapping it has to do resize of console according to frame buffer info. if this resize fails and returns from vc_do_resize() and continues further. At this point console and new frame buffer are mapped and sets display vars. Despite failure still it continue to proceed updating the screen at later stages where vc_data is related to previous frame buffer and frame buffer info and display vars are mapped to new frame buffer and eventully leading to out-of-bounds write in fast_imageblit(). This bheviour is excepted only when fg_console is equal to requested console which is a visible console and updates screen with invalid struct references in fbcon_putcs().

It is possible to read the advisory at git.kernel.org. The identification of this vulnerability is CVE-2025-38685 since 04/16/2025. The exploitation is known to be easy. 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 02/10/2026).

The vulnerability scanner Nessus provides a plugin with the ID 261575 (Linux Distros Unpatched Vulnerability : CVE-2025-38685), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.15.190, 6.1.149, 6.6.103, 6.12.43, 6.15.11, 6.16.2 or 6.17-rc1 eliminates this vulnerability. Applying the patch 078e62bffca4b7e72e8f3550eb063ab981c36c7a/4c4d7ddaf1d43780b106bedc692679f965dc5a3a/27b118aebdd84161c8ff5ce49d9d536f2af10754/ed9b8e5016230868c8d813d9179523f729fec8c6/56701bf9eeb63219e378cb7fcbd066ea4eaeeb50/cfec17721265e72e50cc69c6004fe3475cd38df2/af0db3c1f898144846d4c172531a199bb3ca375d 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 (261575) and CERT Bund (WID-SEC-2025-1976). Be aware that VulDB is the high quality source for vulnerability data.

Affected

  • Debian Linux
  • Amazon Linux 2
  • Open Source Linux Kernel
  • Red Hat Enterprise Linux
  • Ubuntu Linux
  • SUSE Linux
  • Oracle Linux
  • SUSE openSUSE
  • RESF Rocky Linux
  • Microsoft Azure
  • Dell Secure Connect Gateway
  • IBM QRadar SIEM
  • IBM Security Verify Access
  • Dell NetWorker

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.9
VulDB Meta Temp Score: 7.7

VulDB Base Score: 8.0
VulDB Temp Score: 7.6
VulDB Vector: 🔒
VulDB Reliability: 🔍

NVD Base Score: 7.8
NVD Vector: 🔒

CVSSv2info

AVACAuCIA
💳💳💳💳💳💳
💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock

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

Exploitinginfo

Class: Out-of-bounds write
CWE: CWE-787 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-DayUnlockUnlockUnlockUnlock
TodayUnlockUnlockUnlockUnlock

Nessus ID: 261575
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2025-38685

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 5.15.190/6.1.149/6.6.103/6.12.43/6.15.11/6.16.2/6.17-rc1
Patch: 078e62bffca4b7e72e8f3550eb063ab981c36c7a/4c4d7ddaf1d43780b106bedc692679f965dc5a3a/27b118aebdd84161c8ff5ce49d9d536f2af10754/ed9b8e5016230868c8d813d9179523f729fec8c6/56701bf9eeb63219e378cb7fcbd066ea4eaeeb50/cfec17721265e72e50cc69c6004fe3475cd38df2/af0db3c1f898144846d4c172531a199bb3ca375d

Timelineinfo

04/16/2025 CVE reserved
09/04/2025 +141 days Advisory disclosed
09/04/2025 +0 days VulDB entry created
02/10/2026 +159 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2025-38685 (🔒)
GCVE (CVE): GCVE-0-2025-38685
GCVE (VulDB): GCVE-100-322559
CERT Bund: WID-SEC-2025-1976 - Linux Kernel: Mehrere Schwachstellen ermöglichen Denial of Service

Entryinfo

Created: 09/04/2025 18:31
Updated: 02/10/2026 04:39
Changes: 09/04/2025 18:31 (59), 09/05/2025 12:08 (7), 09/07/2025 21:37 (2), 09/29/2025 11:28 (1), 10/08/2025 14:09 (1), 12/02/2025 07:19 (1), 01/09/2026 06:57 (11), 01/14/2026 17:34 (1), 02/10/2026 04:39 (1)
Complete: 🔍
Cache ID: 216::103

Be aware that VulDB is the high quality source for vulnerability data.

Discussion

No comments yet. Languages: en.

Please log in to comment.

◂ PreviousOverviewNext ▸

Do you know our Splunk app?

Download it now for free!