CVE-2026-80578

MMIO disclosure and host disruption via pointer desynchronization

Published Aug 26, 2026 · Updated Aug 27, 2026

Out-of-bounds I/O reads in the Linux kernel fbdev core allow local users to expose MMIO data or disrupt display hardware via /dev/fb*. The fb_io_read() loop advances its hardware source pointer by the full requested chunk after copy_to_user() only partially succeeds, while reducing the remaining count by successful bytes alone. Exploitation requires permission to read an I/O-mapped framebuffer device; crafted reads can disclose adjacent MMIO data, alter read-sensitive device state, or hang or crash the host.

CVSS severity7.3
High
EPSS probability0.12%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds I/O reads in the Linux kernel fbdev core allow local users to expose MMIO data or disrupt display hardware via /dev/fb*. The fb_io_read() loop advances its hardware source pointer by the full requested chunk after copy_to_user() only partially succeeds, while reducing the remaining count by successful bytes alone. Exploitation requires permission to read an I/O-mapped framebuffer device; crafted reads can disclose adjacent MMIO data, alter read-sensitive device state, or hang or crash the host.

The record

CVE
CVE-2026-80578
Published
Aug 26, 2026
Updated
Aug 27, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-125, T1005
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 26, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 27, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=6121cd9ef911432b14c2a17aefaf8cd2f3cfcdff <42a6d8126c194133eafab2b0fd5c8668ebfcba5b
  2. Affected versionversion=6121cd9ef911432b14c2a17aefaf8cd2f3cfcdff <42bc07b4e5a3c8a02a433388f562a8f46d093e11
  3. Affected versionversion=6121cd9ef911432b14c2a17aefaf8cd2f3cfcdff <7110b7b794a2aac2c5cf8eb06ebf2af724c74d50
  4. Affected versionversion=6121cd9ef911432b14c2a17aefaf8cd2f3cfcdff <7ff87a01ae3a8cd0208f7499386998223a8b5dba
  5. Affected versionversion=6121cd9ef911432b14c2a17aefaf8cd2f3cfcdff <81cc73be40c6f028f1ee3f438ace46afe666dbae
  6. Affected versionversion=6.5

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=6121cd9ef911432b14c2a17aefaf8cd2f3cfcdff <42a6d8126c194133eafab2b0fd5c8668ebfcba5b; version=6121cd9ef911432b14c2a17aefaf8cd2f3cfcdff <42bc07b4e5a3c8a02a433388f562a8f46d093e11; version=6121cd9ef911432b14c2a17aefaf8cd2f3cfcdff <7110b7b794a2aac2c5cf8eb06ebf2af724c74d50; version=6121cd9ef911432b14c2a17aefaf8cd2f3cfcdff <7ff87a01ae3a8cd0208f7499386998223a8b5dba; version=6121cd9ef911432b14c2a17aefaf8cd2f3cfcdff <81cc73be40c6f028f1ee3f438ace46afe666dbae; version=6.5

Published CVSS scores

7.3Linux kernel CVE teamCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-125Out-of-bounds Read
T1005Data from Local System

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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