Linux Kernel up to 6.6.152/6.12.104/6.18.45/7.1.9 fbdev fb_io_read out-of-bounds

CVSS Meta Temp Score
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CTI Interest Score
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5.1$0-$5k0.63

Summaryinfo

A vulnerability categorized as problematic has been discovered in Linux Kernel up to 6.6.152/6.12.104/6.18.45/7.1.9. Affected is the function fb_io_read of the component fbdev. Such manipulation leads to out-of-bounds. This vulnerability is referenced as CVE-2026-80578. The attack can only be performed from a local environment. No exploit is available.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.6.152/6.12.104/6.18.45/7.1.9. It has been rated as problematic. Affected by this issue is the function fb_io_read of the component fbdev. The manipulation with an unknown input leads to a out-of-bounds vulnerability. Using CWE to declare the problem leads to CWE-125. The product reads data past the end, or before the beginning, of the intended buffer. Impacted is confidentiality, integrity, and availability. CVE summarizes:

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.

The advisory is shared for download at git.kernel.org. This vulnerability is handled as CVE-2026-80578 since 08/26/2026. The exploitation is known to be easy. The attack needs to be approached locally. There are known technical details, but no exploit is available.

Upgrading to version 6.6.153, 6.12.105, 6.18.46 or 7.1.10 eliminates this vulnerability. Applying the patch 42bc07b4e5a3c8a02a433388f562a8f46d093e11/42a6d8126c194133eafab2b0fd5c8668ebfcba5b/7ff87a01ae3a8cd0208f7499386998223a8b5dba/7110b7b794a2aac2c5cf8eb06ebf2af724c74d50/81cc73be40c6f028f1ee3f438ace46afe666dbae is able to eliminate this problem.

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Productinfo

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Version

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.3
VulDB Meta Temp Score: 5.1

VulDB Base Score: 5.3
VulDB Temp Score: 5.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Out-of-bounds
CWE: CWE-125 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: No

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.6.153/6.12.105/6.18.46/7.1.10
Patch: 42bc07b4e5a3c8a02a433388f562a8f46d093e11/42a6d8126c194133eafab2b0fd5c8668ebfcba5b/7ff87a01ae3a8cd0208f7499386998223a8b5dba/7110b7b794a2aac2c5cf8eb06ebf2af724c74d50/81cc73be40c6f028f1ee3f438ace46afe666dbae

Timelineinfo

08/26/2026 Advisory disclosed
08/26/2026 +0 days CVE reserved
08/26/2026 +0 days VulDB entry created
08/26/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-80578 (🔒)
GCVE (CVE): GCVE-0-2026-80578
GCVE (VulDB): GCVE-100-395900

Entryinfo

Created: 08/26/2026 18:10
Changes: 08/26/2026 18:10 (59)
Complete: 🔍
Cache ID: 216::103

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