CVE-2026-64330

Arbitrary altmode registration via unchecked SVID index

Published Jul 25, 2026 · Updated Jul 25, 2026

Out-of-bounds read in the Linux Kernel TCPM subsystem allows physically proximate attackers to register a chosen USB Type-C altmode. The svdm_consume_modes() function indexes pmdata->svids with pmdata->svid_index without checking it against pmdata->nsvids, so the read reaches partner-supplied VDO data and passes a chosen SVID to typec_partner_register_altmode(). Exploitation requires a malicious USB Type-C partner that supplies crafted Discovery Modes VDOs and advances the SVID index to 20; the demonstrated consequence is arbitrary altmode registration.

CVSS severity2.4
Low
EPSS probability0.13%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Out-of-bounds read in the Linux Kernel TCPM subsystem allows physically proximate attackers to register a chosen USB Type-C altmode. The svdm_consume_modes() function indexes pmdata->svids with pmdata->svid_index without checking it against pmdata->nsvids, so the read reaches partner-supplied VDO data and passes a chosen SVID to typec_partner_register_altmode(). Exploitation requires a malicious USB Type-C partner that supplies crafted Discovery Modes VDOs and advances the SVID index to 20; the demonstrated consequence is arbitrary altmode registration.

The record

CVE
CVE-2026-64330
Published
Jul 25, 2026
Updated
Jul 25, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
T1200
Attack vector
physical
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 25, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 25, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=4.19
  2. Affected versionversion=4ab8c18d4d67321cc7b660559de17511d4fc0237 <012406f89abc52d1d5f07aa5653b519ebf6d2407
  3. Affected versionversion=4ab8c18d4d67321cc7b660559de17511d4fc0237 <313ca06e7e224ca1dfadd5722fe71fb8bc276b8b
  4. Affected versionversion=4ab8c18d4d67321cc7b660559de17511d4fc0237 <3e1b1ac47e8163627f159f30d80d51b914620dd4
  5. Affected versionversion=4ab8c18d4d67321cc7b660559de17511d4fc0237 <7b681dd5fbf60b24a13c14661e5b7735759fb491
  6. Affected versionversion=4ab8c18d4d67321cc7b660559de17511d4fc0237 <89ff289cbf5d3b659a2babc5ccaae4eaf7e7cf53
  7. Affected versionversion=4ab8c18d4d67321cc7b660559de17511d4fc0237 <c6d2af3b217a525741c472f0ab45d7d274b8468f
  8. Affected versionversion=4ab8c18d4d67321cc7b660559de17511d4fc0237 <d638ec188e95fe60f4b01106ffd41958f8fb3c2c
  9. Affected versionversion=4ab8c18d4d67321cc7b660559de17511d4fc0237 <f8163c414de8640f2ca82ce4dc93409d4cdc2fad

What conditions does exploitation require?

Attack vectorphysical
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=4.19; version=4ab8c18d4d67321cc7b660559de17511d4fc0237 <012406f89abc52d1d5f07aa5653b519ebf6d2407; version=4ab8c18d4d67321cc7b660559de17511d4fc0237 <313ca06e7e224ca1dfadd5722fe71fb8bc276b8b; version=4ab8c18d4d67321cc7b660559de17511d4fc0237 <3e1b1ac47e8163627f159f30d80d51b914620dd4; version=4ab8c18d4d67321cc7b660559de17511d4fc0237 <7b681dd5fbf60b24a13c14661e5b7735759fb491; version=4ab8c18d4d67321cc7b660559de17511d4fc0237 <89ff289cbf5d3b659a2babc5ccaae4eaf7e7cf53; version=4ab8c18d4d67321cc7b660559de17511d4fc0237 <c6d2af3b217a525741c472f0ab45d7d274b8468f; version=4ab8c18d4d67321cc7b660559de17511d4fc0237 <d638ec188e95fe60f4b01106ffd41958f8fb3c2c; version=4ab8c18d4d67321cc7b660559de17511d4fc0237 <f8163c414de8640f2ca82ce4dc93409d4cdc2fad

Published CVSS scores

3.5SUSECVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
2.4SUSECVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N

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)
Vectorphysical
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1200Hardware Additions

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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo