SECUFOCUSNOW
Home›CVE index›CVE-2026-80578
ReviewHigh

CVE-2026-80578

Linux

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...

CVSS
7.3
EPSS
-
- percentile
CISA KEV
Not listed
Published
2026.08.27
PRIORITY ASSESSMENT

Review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability-
Technical severityCVSS 7.3

Vulnerability overview

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...

Affected product and versions

Product
Linux
Affected versions
>= 6121cd9ef911432b14c2a17aefaf8cd2f3cfcdff < 42bc07b4e5a3c8a02a433388f562a8f46d093e11, >= 6121cd9ef911432b14c2a17aefaf8cd2f3cfcdff < 42a6d8126c194133eafab2b0fd5c8668ebfcba5b, >= 6121cd9ef911432b14c2a17aefaf8cd2f3cfcdff < 7ff87a01ae3a8cd0208f7499386998223a8b5dba, >= 6121cd9ef911432b14c2a17aefaf8cd2f3cfcdff < 7110b7b794a2aac2c5cf8eb06ebf2af724c74d50, >= 6121cd9ef911432b14c2a17aefaf8cd2f3cfcdff < 81cc73be40c6f028f1ee3f438ace46afe666dbae, >= 6.5
Fixed versions
No verified fixed-version field is available yet

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that Linux and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:H
CWE
Not available