CVE-2026-63871

Bluetooth ISO data race via unlocked route fields

Published Jul 19, 2026 · Updated Jul 19, 2026

Race condition in Bluetooth ISO sockets in Linux Kernel allows local users to trigger a data race through concurrent socket operations. The iso_connect_bis(), iso_connect_cis(), iso_listen_bis(), and iso_conn_big_sync() paths read mutable iso_pi destination, source, and source-type fields in hci_get_route() without holding lock_sock(). Triggering requires connect() or setsockopt() to modify the same socket concurrently; published material reports KCSAN detection but no resulting crash, disclosure, or data change.

CVSS severityUnavailable
Unscored
EPSS probability0.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Race condition in Bluetooth ISO sockets in Linux Kernel allows local users to trigger a data race through concurrent socket operations. The iso_connect_bis(), iso_connect_cis(), iso_listen_bis(), and iso_conn_big_sync() paths read mutable iso_pi destination, source, and source-type fields in hci_get_route() without holding lock_sock(). Triggering requires connect() or setsockopt() to modify the same socket concurrently; published material reports KCSAN detection but no resulting crash, disclosure, or data change.

The record

CVE
CVE-2026-63871
Published
Jul 19, 2026
Updated
Jul 19, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-820
Attack vector
local
Privileges
Unavailable

Timeline

How it unfolded

  1. Jul 19, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 19, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=241f51931c35085449502c10f64fb3ecd6e02171 <859bb1f4cb615d98c9c1ab2bd76ebb0b8fe46020
  2. Affected versionversion=241f51931c35085449502c10f64fb3ecd6e02171 <9798f7d41d85ff763afd1f1cc0533b5c416c8348
  3. Affected versionversion=241f51931c35085449502c10f64fb3ecd6e02171 <9ca7053d6215d89c33f28893bfd1625a32919d3f
  4. Affected versionversion=241f51931c35085449502c10f64fb3ecd6e02171 <ab84fd7779a2a7ff5d2c8eac212c43733f56216e
  5. Affected versionversion=6.1.9 <6.2
  6. Affected versionversion=6.2
  7. Affected versionversion=c524f9561c657b8af26dd4f67092b8928261aa62

What conditions does exploitation require?

Attack vectorlocal
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linux Kernelversion=241f51931c35085449502c10f64fb3ecd6e02171 <859bb1f4cb615d98c9c1ab2bd76ebb0b8fe46020; version=241f51931c35085449502c10f64fb3ecd6e02171 <9798f7d41d85ff763afd1f1cc0533b5c416c8348; version=241f51931c35085449502c10f64fb3ecd6e02171 <9ca7053d6215d89c33f28893bfd1625a32919d3f; version=241f51931c35085449502c10f64fb3ecd6e02171 <ab84fd7779a2a7ff5d2c8eac212c43733f56216e; version=6.1.9 <6.2; version=6.2; version=c524f9561c657b8af26dd4f67092b8928261aa62

Published CVSS scores

No CVSS assessment is available in this record.

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-820Missing Synchronization

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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