CVE-2025-38685
HighIn 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().
CVSS 3.1 score
7.8
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness type
CWE-787CVE-2025-38685 is a Out-of-bounds Write vulnerability
What is Out-of-bounds Write?
The product writes data past the end or before the beginning of the intended buffer. Learn more on MITRE CWE
Affected versions
Linux kernel versions
2.6.12
and later are affected. Fixed in
5.15.190,
6.1.149,
6.6.103,
6.12.43,
6.15.11,
6.16.2,
6.17
and their respective stable series.
References
The following references provide additional information about CVE-2025-38685 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.
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Third Party Advisory
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PatchKernel patch commithttps://git.kernel.org/stable/c/078e62bffca4b7e72e8f3550eb063ab981c36c7a
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PatchKernel patch commithttps://git.kernel.org/stable/c/27b118aebdd84161c8ff5ce49d9d536f2af10754
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PatchKernel patch commithttps://git.kernel.org/stable/c/4c4d7ddaf1d43780b106bedc692679f965dc5a3a
Frequently asked questions
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What is CVE-2025-38685?
CVE-2025-38685 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10 , classified as an Out-of-bounds Write flaw (CWE-787) . It affects Linux kernel versions from 2.6.12 onward and has been patched in 5.15.190, 6.1.149, 6.6.103 and others. CVE-2025-38685 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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What is the CVSS score for CVE-2025-38685?
CVE-2025-38685 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-2025-38685?
Yes — CVE-2025-38685 has been patched. Fixed versions include 5.15.190, 6.1.149, 6.6.103 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.
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Is CVE-2025-38685 actively exploited?
No — CVE-2025-38685 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.
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What is Out-of-bounds Write (CWE-787)?
The product writes data past the end or before the beginning of the intended buffer. View CWE-787 on MITRE CWE →