CVE-2025-40094

Kernel crash via stale USB ACM request

Published Oct 30, 2025 · Updated Aug 5, 2026

NULL pointer dereference in the Linux USB ACM gadget function allows local users to crash the kernel during a failed rebind. After a bind/unbind cycle leaves acm->notify_req stale, acm_bind's unified error path passes that request to gs_free_req, which dereferences ep->ops->free_request. Exploitation requires local access capable of reconfiguring the USB gadget and causing a later bind failure; the documented outcome is a kernel oops or panic.

CVSS severity7.8
High
EPSS probability0.14%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

NULL pointer dereference in the Linux USB ACM gadget function allows local users to crash the kernel during a failed rebind. After a bind/unbind cycle leaves acm->notify_req stale, acm_bind's unified error path passes that request to gs_free_req, which dereferences ep->ops->free_request. Exploitation requires local access capable of reconfiguring the USB gadget and causing a later bind failure; the documented outcome is a kernel oops or panic.

The record

CVE
CVE-2025-40094
Published
Oct 30, 2025
Updated
Aug 5, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 30, 2025CVE publishedPublication date reported by the CVE source.
  2. Aug 5, 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=1f1ba11b64947051fc32aa15fcccef6463b433f7 <201a66d8e6630762e760e1d78f1d149da1691e7b
  2. Affected versionversion=1f1ba11b64947051fc32aa15fcccef6463b433f7 <2b1546f7c5fc6c44555a8e7a2b34229d1dcd2175
  3. Affected versionversion=1f1ba11b64947051fc32aa15fcccef6463b433f7 <47b2116e54b4a854600341487e8b55249e926324
  4. Affected versionversion=1f1ba11b64947051fc32aa15fcccef6463b433f7 <c4301e4dd6b32faccb744f1c2320e64235b68d3b
  5. Affected versionversion=1f1ba11b64947051fc32aa15fcccef6463b433f7 <c5d116862dd3ed162d079738a5ebddf9fceea850
  6. Affected versionversion=1f1ba11b64947051fc32aa15fcccef6463b433f7 <e348d18fb0124b662cfefb3001733b49da428215
  7. Affected versionversion=2.6.27

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=1f1ba11b64947051fc32aa15fcccef6463b433f7 <201a66d8e6630762e760e1d78f1d149da1691e7b; version=1f1ba11b64947051fc32aa15fcccef6463b433f7 <2b1546f7c5fc6c44555a8e7a2b34229d1dcd2175; version=1f1ba11b64947051fc32aa15fcccef6463b433f7 <47b2116e54b4a854600341487e8b55249e926324; version=1f1ba11b64947051fc32aa15fcccef6463b433f7 <c4301e4dd6b32faccb744f1c2320e64235b68d3b; version=1f1ba11b64947051fc32aa15fcccef6463b433f7 <c5d116862dd3ed162d079738a5ebddf9fceea850; version=1f1ba11b64947051fc32aa15fcccef6463b433f7 <e348d18fb0124b662cfefb3001733b49da428215; version=2.6.27

Published CVSS scores

7.8kernel.orgCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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

T1499.004Application or System Exploitation

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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