CVE-2025-68237

Kernel crash via overflowing mtdchar request bounds

Published Dec 16, 2025 · Updated Dec 16, 2025

Integer overflow in affected Linux releases from 5.17 allows local users to crash the system through crafted MTD read or write ioctls. In drivers/mtd/mtdchar.c, mtdchar masks req.len to 32 bits but adds it to an unchecked 64-bit req.start, allowing the request end to wrap. Reachability requires local low-privileged access and an available MTD character device; the bounded consequence is a kernel crash.

CVSS severity5.5
Medium
EPSS probability0.19%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Integer overflow in affected Linux releases from 5.17 allows local users to crash the system through crafted MTD read or write ioctls. In drivers/mtd/mtdchar.c, mtdchar masks req.len to 32 bits but adds it to an unchecked 64-bit req.start, allowing the request end to wrap. Reachability requires local low-privileged access and an available MTD character device; the bounded consequence is a kernel crash.

The record

CVE
CVE-2025-68237
Published
Dec 16, 2025
Updated
Dec 16, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 16, 2025CVE publishedPublication date reported by the CVE source.
  2. Dec 16, 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=5.17
  2. Affected versionversion=6420ac0af95dbcb2fd8452e2d551ab50e1bbad83 <37944f4f8199cd153fef74e95ca268020162f212
  3. Affected versionversion=6420ac0af95dbcb2fd8452e2d551ab50e1bbad83 <457376c6fbf0c69326a9bf1f72416225f681192b
  4. Affected versionversion=6420ac0af95dbcb2fd8452e2d551ab50e1bbad83 <e4185bed738da755b191aa3f2e16e8b48450e1b8
  5. Affected versionversion=6420ac0af95dbcb2fd8452e2d551ab50e1bbad83 <eb9361484814fb12f3b7544b33835ea67d7a6a97
  6. Affected versionversion=6420ac0af95dbcb2fd8452e2d551ab50e1bbad83 <f37efdd97fd1ec3e0d0f1eec279c8279e28f981e

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.17; version=6420ac0af95dbcb2fd8452e2d551ab50e1bbad83 <37944f4f8199cd153fef74e95ca268020162f212; version=6420ac0af95dbcb2fd8452e2d551ab50e1bbad83 <457376c6fbf0c69326a9bf1f72416225f681192b; version=6420ac0af95dbcb2fd8452e2d551ab50e1bbad83 <e4185bed738da755b191aa3f2e16e8b48450e1b8; version=6420ac0af95dbcb2fd8452e2d551ab50e1bbad83 <eb9361484814fb12f3b7544b33835ea67d7a6a97; version=6420ac0af95dbcb2fd8452e2d551ab50e1bbad83 <f37efdd97fd1ec3e0d0f1eec279c8279e28f981e

Published CVSS scores

5.5SUSECVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/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.

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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

T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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