CVE-2026-63893 | Vulnerability Intelligence

Stored catalog record

Source record retrieved 2026-10-28T10:25:50.306167+00:00. Scheduled imports handle updates; this page does not assert that the provider was queried just now.

Vulnerability overview

In the Linux kernel, the following vulnerability has been resolved: thunderbolt: property: Reject u32 wrap in tb_property_entry_valid() entry->value is u32 and entry->length is u16; the sum is performed in u32 and wraps. A malicious XDomain peer can pick value = 0xffffff00, length = 0x100 so the sum 0x100000000 wraps to 0 and passes the > block_len check. tb_property_parse() then passes entry->value to parse_dwdata() as a dword offset into the property block, reading attacker-directed memory far past the allocation. For TEXT-typed entries with the "deviceid" or "vendorid" keys this lands in xd->device_name / xd->vendor_name and is readable back via the per-XDomain device_name / vendor_name sysfs attributes; the leak is NUL-bounded (kstrdup() stops at the first zero byte) and untargeted (the attacker picks a delta, not an absolute address). DATA-typed entries are parsed into property->value.data but not generically surfaced to userspace. Use check_add_overflow() so a wrapped sum is rejected.

Patch review priority

Assess exposure and vendor guidance

No higher-priority signal is available in the current stored evidence.

FIRST EPSS: 0.39% · percentile 32.6 · score date 2026-10-27.

EPSS estimates probability of exploitation in the next 30 days. It does not measure your exposure or prove exploitation. The elevated threshold is 10%; CISA KEV takes precedence. About FIRST EPSS ↗

Severity and scoring

CVSS score: 8.1 · HIGH
CVSS version: 3.1
CVSS vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
Weaknesses: CWE-190

CVSS measures technical severity; it does not establish whether this vulnerability is being exploited in your environment.

Known exploitation and remediation

Not listed in the CISA catalog retrieved for this record. This does not establish that exploitation has not occurred.

Verify affected versions and patch availability in the vendor advisory before making changes.

Affected products and versions

cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
From (inclusive): 4.15
Before (exclusive): 5.10.259
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
From (inclusive): 5.11
Before (exclusive): 5.15.210
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
From (inclusive): 5.16
Before (exclusive): 6.1.176
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
From (inclusive): 6.2
Before (exclusive): 6.6.143
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
From (inclusive): 6.7
Before (exclusive): 6.12.93
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
From (inclusive): 6.13
Before (exclusive): 6.18.35
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
From (inclusive): 6.19
Before (exclusive): 7.0.12
cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:7.1:rc5:*:*:*:*:*:*

These are NVD CPE applicability entries. Some products depend on configuration conditions; consult the official record to confirm applicability.

Advisories and references

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