CVE-2026-63891: Linux kernel · thunderbolt: property: Cap recursion depth in __tb_property_parse_dir()
Affects Linux kernelSource GCVE Database
Not known to be exploited.
Data as of 12 Nov 2026, 20:41 UTC
Rated High by Threat Radar's AI analysis · No CVSS score from NVD or the CNA
Thin evidence
One scorer or noneExploitation evidence
Disclosed: evidence found.
CVE published 19 Jul 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 12 Nov 2026.
What to do
AI-suggested
The vulnerability is fixed by adding a recursion depth limit of 8 in the Thunderbolt property parser. Operators who do not require XDomain host-to-host discovery can disable this feature entirely by setting the kernel command line parameter thunderbolt.xdomain=0. No other immediate actions are required if the system is updated with the fix or the feature is disabled.
Description
A vulnerability in the Linux kernel's Thunderbolt property parser allows untrusted XDomain peers to trigger a stack exhaustion via recursive directory entries without authentication. This can cause a kernel stack overflow and trigger a guard page fault. The issue is addressed by limiting recursion depth to 8 and can be mitigated by disabling XDomain host-to-host discovery if not needed.
References
- git.kernel.org/stable/c/2b5f47a710172c962ef42d1b732b04d2ad0dce21 (opens in a new tab)
- git.kernel.org/stable/c/95839a67ea56ca35732aad7f711404a3127cfe2d (opens in a new tab)
- git.kernel.org/stable/c/0a84ab9271936c11e84e511bb52fc5682f8b6726 (opens in a new tab)
- git.kernel.org/stable/c/b4621e5ef63405c317a84b711faf3bd75b3c6a94 (opens in a new tab)
- git.kernel.org/stable/c/f31c6d220f455b5af63590302b30e1b932d14599 (opens in a new tab)
- git.kernel.org/stable/c/830c8a9b467e7d3a158483d37fa7dc13892b293a (opens in a new tab)
- git.kernel.org/stable/c/ed9455ef4bd9babc90f92e526abe3fb68c1a8709 (opens in a new tab)
- git.kernel.org/stable/c/928abe19fbf0127003abcb1ea69cabc1c897d0ab (opens in a new tab)