CVE-2025-40304

High

In the Linux kernel, the following vulnerability has been resolved: fbdev: Add bounds checking in bit_putcs to fix vmalloc-out-of-bounds Add bounds checking to prevent writes past framebuffer boundaries when rendering text near screen edges. Return early if the Y position is off-screen and clip image height to screen boundary. Break from the rendering loop if the X position is off-screen. When clipping image width to fit the screen, update the character count to match the clipped width to prevent buffer size mismatches. Without the character count update, bit_putcs_aligned and bit_putcs_unaligned receive mismatched parameters where the buffer is allocated for the clipped width but cnt reflects the original larger count, causing out-of-bounds writes.

Package Linux Kernel
Published 2025-12-08
Last modified 2026-07-30
CVSS version 3.1
Patch available
Yes

CVSS 3.1 score

7.8

out of 10
High
Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected versions

Linux kernel versions 2.6.12 and later are affected. Fixed in 5.4.302, 5.10.247, 5.15.197, 6.1.159, 6.6.117, 6.12.58, 6.17.8, 6.18 and their respective stable series.

Affected from
≥ 2.6.12
Fixed in
✓ 5.4.302 5.4.x ✓ 5.10.247 5.10.x ✓ 5.15.197 5.15.x ✓ 6.1.159 6.1.x ✓ 6.6.117 6.6.x ✓ 6.12.58 6.12.x ✓ 6.17.8 6.17.x ✓ 6.18

References

8 total
Showing 5 of 8 references View all on NVD

Frequently asked questions

  • What is CVE-2025-40304?

    CVE-2025-40304 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10 . It affects Linux kernel versions from 2.6.12 onward and has been patched in 5.4.302, 5.10.247, 5.15.197 and others. CVE-2025-40304 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2025-40304?

    CVE-2025-40304 has a CVSS score of 7.8 out of 10, rated High severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H .

  • Is there a patch available for CVE-2025-40304?

    Yes. CVE-2025-40304 has been patched. Fixed versions include 5.4.302, 5.10.247, 5.15.197 and others. If you are running Linux kernel 2.6.12 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2025-40304 actively exploited?

    No. CVE-2025-40304 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

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