Out-of-bounds read in Linux kernel Thunderbolt XDomain handling
Key facts
- Attack vector
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- Privileges required
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- User interaction
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- Attack complexity
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- Impact type
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- Confidentiality · integrity · availability
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- Fix status
- Partial Red Hat: 6 without a fix
No CVSS vector from any source. Fix status from CNA and Red Hat.
Summary
The Linux kernel thunderbolt driver from 4.15 does not reject XDomain properties responses whose length field exceeds the allocated buffer. A malicious peer can set that six-bit length to 63, which makes the driver copy past the end of a heap buffer and read 12 bytes out of bounds.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
Description from the CNA
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.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 4.15 and later | 5.10.273, 5.15.224, 6.1.191, 6.6.160, 6.12.113, 6.18.56, 7.2.10, 7.3 | Patch available | CNA |
- Linux VendorLinux Affected 4.15 and later Fixed in 5.10.273, 5.15.224, 6.1.191, 6.6.160, 6.12.113, 6.18.56, 7.2.10, 7.3 Patch available CNA
Remediation
Update the Linux kernel to 5.10.273, 5.15.224, 6.1.191, 6.6.160, 6.12.113, 6.18.56, 7.2.10 or 7.3. Red Hat Enterprise Linux 7, 8, 9, 10 and OpenShift Container Platform 4 and 5 are affected, and Red Hat lists no fix available for them.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
- Fix · CNA Linux (Linux) Fixed in 5.10.273, 5.15.224, 6.1.191, 6.6.160, 6.12.113, 6.18.56, 7.2.10, 7.3
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 7 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 8 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 9 | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift Container Platform 4 | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift Container Platform 5 | Affected | No fix yet: Fix deferred |
Not affected: 1 product
- Red Hat Enterprise Linux 6
Timeline
- 2026-10-18 Threatist record created from CVE-2026-98687
- 2026-10-18 Alias added: GHSA-rq3j-rw4p-w59w
- 2026-10-19 Fix available: Linux/[email protected] · CNA
- 2026-10-21 Fix available: Linux/[email protected], Linux/Linux@b270c1074860de74da0d6b5250fb06b359b9d509 · CNA
- 2026-10-21 1 new reference · CNA
- 2026-10-23 Affected versions changed · Red Hat
- 2026-10-23 CVSS score added · Red Hat
- 2026-10-30 Affected versions changed · Red Hat
- 2026-10-30 Fix available: Linux/Linux@37ea4304bd9f57ebe719409f010915495467f05c, Linux/[email protected], Linux/[email protected] +3 · CNA
- 2026-10-30 3 new references · CNA
References
Other 8
- 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
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Sources
- CVE-2026-98687 · CVE Program
- CVE-2026-98687 · NVD
- FIRST EPSS
- GHSA-rq3j-rw4p-w59w · GitHub Advisory Database · CC BY 4.0
- CVE-2026-98687 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences