CVE-2026-63891: linux

CVSS: UnknownAwaiting analysis
AliasesUBUNTU-CVE-2026-63891DEBIAN-CVE-2026-63891
Published 19-07-2026Last modified 19-07-2026
Open JSON

Vulnerability summary

CVE-2026-63891 is a vulnerability in linux with no CVSS score yet. EPSS estimates a 0.27% chance of exploitation in the next 30 days, higher than 18.7% of scored vulnerabilities.

Overall risk
0/100
0100
Minimal · default modelHow is this calculated?
CVSS score
Not scored
010
No CVSS score recorded
EPSS score
0.27%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 31 · Related 31
OPENSUSE-SU-2026:21910-1SUSE-SU-2026:23477-1SUSE-SU-2026:23481-1SUSE-SU-2026:23528-1SUSE-SU-2026:23529-1SUSE-SU-2026:23881-1

Timeline

  1. 19-07-2026
    PublishedVulnerability first disclosed.

Description

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 metrics

Risk metrics not yet published.

EPSS trend

Probability

0.27%

Chance of exploitation in the next 30 days

Percentile

19%

Versus all other CVEs

30-day change

0.00 pp

From 0.27% on 20-09-2026

20-09-202620-10-2026
EPSS score
0.27%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

No weakness data has been published for this record.

Affected systems

Ubuntu166 products
  • linuxAll versions (No fix recorded) | < 5.15.0-198.208 | < 6.8.0-146.146 | < 7.0.0-28.28
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-awsAll versions (No fix recorded) | < 5.15.0-1117.124 | < 6.8.0-1066.69 | < 7.0.0-1009.9
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Debian1 product
  • linux< 6.1.176-1 | < 6.12.94-1 | < 7.0.12-1
Linux1 product
  • linux≥ cdae7c07e3e3509eaabc18c1640a55dc5b99c179, < 2b5f47a710172c962ef42d1b732b04d2ad0dce21 | ≥ cdae7c07e3e3509eaabc18c1640a55dc5b99c179, < 95839a67ea56ca35732aad7f711404a3127cfe2d | ≥ cdae7c07e3e3509eaabc18c1640a55dc5b99c179, < 0a84ab9271936c11e84e511bb52fc5682f8b6726 | ≥ cdae7c07e3e3509eaabc18c1640a55dc5b99c179, < b4621e5ef63405c317a84b711faf3bd75b3c6a94 | ≥ cdae7c07e3e3509eaabc18c1640a55dc5b99c179, < f31c6d220f455b5af63590302b30e1b932d14599 | ≥ cdae7c07e3e3509eaabc18c1640a55dc5b99c179, < 830c8a9b467e7d3a158483d37fa7dc13892b293a | ≥ cdae7c07e3e3509eaabc18c1640a55dc5b99c179, < ed9455ef4bd9babc90f92e526abe3fb68c1a8709 | ≥ cdae7c07e3e3509eaabc18c1640a55dc5b99c179, < 928abe19fbf0127003abcb1ea69cabc1c897d0ab | 4.15

3 vendors · 168 products

References

31 links
Show all 31 references