CVE-2025-39680

Kernel memory exposure and corruption via unchecked length

Published Sep 5, 2025 · Updated Sep 5, 2025

Out-of-bounds access in the Linux kernel rtl9300 I2C driver allows local users to expose or corrupt kernel memory through an SMBus ioctl. rtl9300_i2c_smbus_xfer accepts the user-controlled data->block[0] value as a transfer length without validating its range, driving out-of-bounds reads and writes. Exploitation requires access to a local /dev/i2c device on RTL9300 hardware and can disclose adjacent kernel stack data, corrupt memory, or crash the system.

CVSS severity7.8
High
EPSS probability0.15%
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 access in the Linux kernel rtl9300 I2C driver allows local users to expose or corrupt kernel memory through an SMBus ioctl. rtl9300_i2c_smbus_xfer accepts the user-controlled data->block[0] value as a transfer length without validating its range, driving out-of-bounds reads and writes. Exploitation requires access to a local /dev/i2c device on RTL9300 hardware and can disclose adjacent kernel stack data, corrupt memory, or crash the system.

The record

CVE
CVE-2025-39680
Published
Sep 5, 2025
Updated
Sep 5, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-125, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 5, 2025CVE publishedPublication date reported by the CVE source.
  2. Sep 5, 2025Record 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=6.13
  2. Affected versionversion=c366be720235301fdadf67e6f1ea6ff32669c074 <071e43fcba5ddd9a7813e6cc0aa10299eae41b21
  3. Affected versionversion=c366be720235301fdadf67e6f1ea6ff32669c074 <57f312b955938fc4663f430cb57a71f2414f601b

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=6.13; version=c366be720235301fdadf67e6f1ea6ff32669c074 <071e43fcba5ddd9a7813e6cc0aa10299eae41b21; version=c366be720235301fdadf67e6f1ea6ff32669c074 <57f312b955938fc4663f430cb57a71f2414f601b

Published CVSS scores

7.8Linux CNACVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
7.1NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 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
T1068Exploitation for Privilege Escalation

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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