CVE-2026-80578

High

In the Linux kernel, the following vulnerability has been resolved: fbdev: core: Fix pointer desynchronization in fb_io_read() In fb_io_read(), if copy_to_user() performs a partial copy (e.g., due to a faulty user buffer), the loop adjusts the chunk size 'c' and updates the remaining 'count'. However, the hardware 'src' pointer has already been eagerly advanced by the original chunk size. If the loop is allowed to continue, the read will resume from an incorrect, over-advanced offset. Since the remaining 'count' was only decremented by the successful bytes, this desynchronization causes the next iterations to execute more hardware reads than originally bounded, eventually leading to out-of-bounds I/O reads. Fix this by breaking out of the loop immediately upon a partial copy_to_user(). A partial copy indicates a faulty user buffer, making subsequent read attempts futile. Breaking out ensures we return the number of successfully read bytes without risking out-of-bounds hardware accesses in subsequent mismatched iterations.

Package Linux Kernel
Published 2026-08-26
Last modified 2026-08-27
CVSS version 3.1
Patch available
Yes

CVSS 3.1 score

7.3

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

Affected versions

Linux kernel versions 6.5 and later are affected. Fixed in 6.6.153, 6.12.105, 6.18.46, 7.1.10, 7.2 and their respective stable series.

Affected from
≥ 6.5
Fixed in
✓ 6.6.153 6.6.x ✓ 6.12.105 6.12.x ✓ 6.18.46 6.18.x ✓ 7.1.10 7.1.x ✓ 7.2

References

5 total

Frequently asked questions

  • What is CVE-2026-80578?

    CVE-2026-80578 is a High severity Linux kernel vulnerability with a CVSS score of 7.3 out of 10 . It affects Linux kernel versions from 6.5 onward and has been patched in 6.6.153, 6.12.105, 6.18.46 and others. CVE-2026-80578 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2026-80578?

    CVE-2026-80578 has a CVSS score of 7.3 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:L/A:H .

  • Is there a patch available for CVE-2026-80578?

    Yes. CVE-2026-80578 has been patched. Fixed versions include 6.6.153, 6.12.105, 6.18.46 and others. If you are running Linux kernel 6.5 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2026-80578 actively exploited?

    No. CVE-2026-80578 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

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