CVE-2026-63891

UNRATEDCVSS · not yet scoredTrending — 3 sources updated this week
—
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • No CVSS published and no exploitation signals yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS v2: —Exploit: None knownExposed: 0

A fix is available — apply it.

In the Linux kernel, the following vulnerability has been resolved:

thunderbolt: property: Cap recursion depth in __tb_property_parse_dir()

A DIRECTORY entry's value field is used as the dir_offset for a recursive call into __tb_property_parse_dir() with no depth counter. A crafted peer that chains DIRECTORY entries into a back-reference loop drives the parser until the kernel stack is exhausted and the guard page fires. Any untrusted XDomain peer (cable, dock, in-line inspector, adjacent host) that reaches the PROPERTIES_REQUEST control-plane exchange can trigger this without authentication.

Thread a depth counter through tb_property_parse() and __tb_property_parse_dir(), and reject blocks that exceed TB_PROPERTY_MAX_DEPTH = 8. That is comfortably larger than any observed legitimate XDomain layout.

Operators who do not need XDomain host-to-host discovery can disable the path entirely with thunderbolt.xdomain=0 on the kernel command line.

CVSS v3
—
EchelonGraph score
Not yet assessedNo source has published severity data for this CVE yet — no CVSS score from NVD or a CNA, no GitHub advisory, and it is not in CISA KEV. This is not a rating of zero; we cannot assess it yet.
EG Score
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EG Risk
—
EPSS PROB
0%
EPSS %ILE
19%
KEV
Not listed

Published

July 19, 2026

Last Modified

July 27, 2026

References (8)

Vendor Advisories for CVE-2026-63891(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(5)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntulinux-tools-oracle-7.0 (7.0.0-1008.8) @ resolute2026-08-30ubuntu
ubuntulinux-tools-nvidia-hwe-26.04 (7.0.0-2016.16) @ resolute2026-08-30ubuntu
ubuntulinux-tools-raspi-realtime-7.0 (7.0.0-1015.15) @ resolute2026-08-30ubuntu
ubuntulinux-tools-nvidia-hwe-24.04-edge (7.0.0-1016.16) @ resolute2026-08-30ubuntu
ubuntulinux-tools-azure-fde-7.0 (7.0.0-1009.9) @ resolute2026-08-30ubuntu

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(4 across 4 ecosystems)
Debian:11(1)
PackageVulnerable rangeFixed inDependents
linux5.10.103-1 ... 5.10.92-2 (54 versions)5.10.259-1—
Debian:12(1)
PackageVulnerable rangeFixed inDependents
linux6.1.106-1 ... 6.1.99-1 (53 versions)6.1.176-1—
Debian:13(1)
PackageVulnerable rangeFixed inDependents
linux6.12.38-1 ... 6.12.94-1~bpo12+1 (27 versions)6.12.94-1—
Debian:14(1)
PackageVulnerable rangeFixed inDependents
linux6.12.100-1 ... 7.0.9-1~bpo13+1 (138 versions)7.0.12-1—

All Vendor Advisories

(5)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

(refreshed 8× in last 7d / 44× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-08-30 02:58 UTCVendor advisory
  2. 2026-08-30 02:58 UTCGHSA enrichment
  3. 2026-08-30 01:22 UTCEPSS rescore
  4. 2026-08-28 21:42 UTCEPSS rescore
  5. 2026-08-27 14:25 UTCEPSS rescore
  6. 2026-08-26 14:46 UTCEPSS rescore
  7. 2026-08-25 18:49 UTCGHSA enrichment
  8. 2026-08-25 13:49 UTCEPSS rescore
  9. 2026-08-23 00:19 UTCEPSS rescore
  10. 2026-08-22 20:28 UTCVendor advisory
  11. 2026-08-22 20:28 UTCGHSA enrichment
  12. 2026-08-21 23:49 UTCEPSS rescore
  13. 2026-08-20 22:55 UTCEPSS rescore
  14. 2026-08-19 23:11 UTCVendor advisory
  15. 2026-08-19 23:11 UTCGHSA enrichment
  16. 2026-08-19 17:04 UTCEPSS rescore
  17. 2026-08-18 13:48 UTCEPSS rescore
  18. 2026-08-17 13:47 UTCEPSS rescore
  19. 2026-08-16 23:00 UTCVendor advisory
  20. 2026-08-16 23:00 UTCGHSA enrichment
  21. 2026-08-16 14:56 UTCEPSS rescore
  22. 2026-08-15 01:30 UTCEPSS rescore
  23. 2026-08-14 01:43 UTCVendor advisory
  24. 2026-08-14 01:43 UTCGHSA enrichment
  25. 2026-08-13 22:00 UTCEPSS rescore
Show 49 more
  1. 2026-08-12 13:51 UTCEPSS rescore
  2. 2026-08-11 04:27 UTCVendor advisory
  3. 2026-08-11 04:27 UTCGHSA enrichment
  4. 2026-08-11 00:00 UTCEPSS rescore
  5. 2026-08-09 13:47 UTCEPSS rescore
  6. 2026-08-08 16:37 UTCEPSS rescore
  7. 2026-08-08 07:11 UTCVendor advisory
  8. 2026-08-08 07:11 UTCGHSA enrichment
  9. 2026-08-06 13:47 UTCEPSS rescore
  10. 2026-08-05 19:17 UTCEPSS rescore
  11. 2026-08-05 19:17 UTCEPSS rescore
  12. 2026-08-05 09:54 UTCGHSA enrichment
  13. 2026-08-04 15:10 UTCEPSS rescore
  14. 2026-08-04 10:39 UTCEPSS rescore
  15. 2026-08-03 10:36 UTCEPSS rescore
  16. 2026-08-02 12:25 UTCVendor advisory
  17. 2026-08-02 12:25 UTCGHSA enrichment
  18. 2026-08-02 02:27 UTCEPSS rescore
  19. 2026-08-01 04:16 UTCEPSS rescore
  20. 2026-07-30 16:28 UTCEPSS rescore
  21. 2026-07-30 15:09 UTCEG score recompute
  22. 2026-07-30 15:08 UTCGHSA enrichment
  23. 2026-07-30 01:30 UTCEPSS rescore
  24. 2026-07-30 01:30 UTCEPSS rescore
  25. 2026-07-28 15:37 UTCEPSS rescore
  26. 2026-07-27 17:51 UTCGHSA enrichment
  27. 2026-07-27 14:14 UTCEPSS rescore
  28. 2026-07-26 14:54 UTCEPSS rescore
  29. 2026-07-26 14:54 UTCEPSS rescore
  30. 2026-07-26 11:01 UTCEG score recompute
  31. 2026-07-26 11:01 UTCVendor advisory
  32. 2026-07-26 11:01 UTCGHSA enrichment
  33. 2026-07-25 14:18 UTCEPSS rescore
  34. 2026-07-25 14:18 UTCEPSS rescore
  35. 2026-07-24 14:18 UTCEPSS rescore
  36. 2026-07-24 14:18 UTCEPSS rescore
  37. 2026-07-23 14:18 UTCEPSS rescore
  38. 2026-07-23 14:18 UTCEPSS rescore
  39. 2026-07-23 03:22 UTCEG score recompute
  40. 2026-07-22 14:08 UTCEPSS rescore
  41. 2026-07-22 14:08 UTCEPSS rescore
  42. 2026-07-21 15:25 UTCEPSS rescore
  43. 2026-07-21 15:25 UTCEPSS rescore
  44. 2026-07-20 17:38 UTCEG score recompute
  45. 2026-07-20 17:38 UTCGHSA enrichment
  46. 2026-07-20 17:08 UTCEPSS rescore
  47. 2026-07-19 17:49 UTCNVD update
  48. 2026-07-19 15:24 UTCEG score recompute
  49. 2026-07-19 15:19 UTCMITRE cvelistV5first tracked

Frequently asked(4)

What is CVE-2026-63891?
CVE-2026-63891 is a publicly disclosed vulnerability published on July 19, 2026. In the Linux kernel, the following vulnerability has been resolved: thunderbolt: property: Cap recursion depth in tbpropertyparse_dir() A DIRECTORY entry's value field is used as the dir_offset for a recursive call into tbpropertyparse_dir() with no depth counter. A crafted peer that chains…
When was CVE-2026-63891 disclosed?
CVE-2026-63891 was first published in the National Vulnerability Database on July 19, 2026, with the most recent update on July 27, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-63891 actively exploited?
CVE-2026-63891 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 80.5% of all scored CVEs.
How do I remediate CVE-2026-63891?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-63891, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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