VulnerabilityPublished 18 Oct 2026Updated 21 Oct 2026

CVE-2026-98687: Linux kernel · thunderbolt: Reject oversized XDomain properties responses

Affects Linux kernelSource CVE Database V5

Not known to be exploited · fixed in b270c1074860de74da0d6b5250fb06b359b9d509 : update Linux kernel when convenient.

Data as of 26 Oct 2026, 20:25 UTC

Severity

Medium

Rated Medium by Threat Radar's AI analysis · CVSS not yet scored by NVD

EPSS: 0.1% chance of exploitation in 30 days – higher than 5% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in b270c1074860de74da0d6b5250fb06b359b9d509, a766a86ff48acee76aeb8e2575771040749e509d, 80756e263846ab694984e749e8c626897331438f +2

Exploitation evidence

Disclosed: evidence found.
CVE published 18 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ d1ff70241a275133e1a0258b7c23588b122276c8, < b270c1074860de74da0d6b5250fb06b359b9d509	Fixed in b270c1074860de74da0d6b5250fb06b359b9d509
LinuxLinux	Affected ≥ d1ff70241a275133e1a0258b7c23588b122276c8, < a766a86ff48acee76aeb8e2575771040749e509d	Fixed in a766a86ff48acee76aeb8e2575771040749e509d
LinuxLinux	Affected ≥ d1ff70241a275133e1a0258b7c23588b122276c8, < 80756e263846ab694984e749e8c626897331438f	Fixed in 80756e263846ab694984e749e8c626897331438f
LinuxLinux	Affected ≥ d1ff70241a275133e1a0258b7c23588b122276c8, < 737a1d2e9642d5f718bd29aa4a98b9eef3832f0a	Fixed in 737a1d2e9642d5f718bd29aa4a98b9eef3832f0a
LinuxLinux	Affected ≥ d1ff70241a275133e1a0258b7c23588b122276c8, < 2f97f929dad9eb3e1f63b721d2dd49bf9bc68efa	Fixed in 2f97f929dad9eb3e1f63b721d2dd49bf9bc68efa
LinuxLinux	Affected =4.15	Fixed in–

AI-suggested

A fix is available in the Linux kernel as indicated by multiple fixed commit versions. Users should update their Linux kernel to a version that includes these fixes to mitigate this vulnerability.

Description

A vulnerability in the Linux kernel's Thunderbolt driver allows a malicious peer to trigger a heap out-of-bounds read by sending an oversized XDomain properties response. The driver allocates a fixed-size buffer but does not properly validate the length field in the response, leading to reading beyond the allocated memory. This issue has been resolved by rejecting response data lengths that exceed the allocated buffer before copying.

Impact

This vulnerability causes a heap out-of-bounds read in the Linux kernel's Thunderbolt driver, which may lead to information disclosure or kernel instability. There is no indication of known exploits in the wild. The impact is limited to the affected kernel component and requires a malicious peer to send crafted XDomain responses.

Summary

The Linux kernel Thunderbolt driver function tb_xdp_properties_request() allocates a 252-byte buffer for XDomain properties responses, expecting up to 45 data dwords. However, the XDomain length field is 6 bits wide and can be set maliciously to 63, which after subtracting fixed fields is treated as 48 data dwords. This causes memcpy() to read 192 bytes from a 180-byte array, resulting in a 12-byte heap out-of-bounds read. The vulnerability was addressed by adding checks to reject response data lengths exceeding the allocated buffer before copying into the property block.

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 26 Oct 2026, 20:25 UTC

Technical details

References

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