Kernel resource leak via unreleased L2CAP channel reference
Published Jul 19, 2026 · Updated Jul 19, 2026
Resource leak in the Linux kernel Bluetooth L2CAP subsystem allows attackers to retain channel references through timed-out channels. __set_chan_timer() acquires a l2cap_chan reference before delayed work, but l2cap_chan_timeout() returns when chan->conn is NULL without calling l2cap_chan_put(). The public record does not identify a trigger path or claim a crash, so the documented consequence is limited to unreleased kernel resources.
Summary
What happened
Resource leak in the Linux kernel Bluetooth L2CAP subsystem allows attackers to retain channel references through timed-out channels. __set_chan_timer() acquires a l2cap_chan reference before delayed work, but l2cap_chan_timeout() returns when chan->conn is NULL without calling l2cap_chan_put(). The public record does not identify a trigger path or claim a crash, so the documented consequence is limited to unreleased kernel resources.
The record
- CVE
- CVE-2026-63948
- Published
- Jul 19, 2026
- Updated
- Jul 19, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux Kernel
- Classifications
- Unavailable
- Attack vector
- Unavailable
- Privileges
- Unavailable
Timeline
How it unfolded
- Jul 19, 2026CVE publishedPublication date reported by the CVE source.
- Jul 19, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=06acb75e7ed600d0bbf7bff5628aa8f24a97978c <50f1bcaaaa3a80bb1c3472044bc146e8d49d51ee
- Affected versionversion=4.19.314 <4.20
- Affected versionversion=5.10.217 <5.10.259
- Affected versionversion=5.15.159 <5.15.210
- Affected versionversion=5.4.276 <5.5
- Affected versionversion=6.1.91 <6.1.176
- Affected versionversion=6466ee65e5b27161c846c73ef407f49dfa1bd1d9
- Affected versionversion=6.6.31 <6.6.143
- Affected versionversion=6.8.10 <6.9
- Affected versionversion=6.9
- Affected versionversion=8960ff650aec70485b40771cd8e6e8c4cb467d33 <8894c2010435a56ce7c6c2a8785860c13554df2f
- Affected versionversion=955b5b6c54d95b5e7444dfc81c95c8e013f27ac0 <63cd225cc13d782a85e2a73c04d0d350153eada1
- Affected versionversion=adf0398cee86643b8eacde95f17d073d022f782c <08d81fe96f80a8e20c7acb573b6a45d901fcf2cd
- Affected versionversion=adf0398cee86643b8eacde95f17d073d022f782c <107c826e4ef9ec5ad8f60e6fe64d8d5325ba508f
- Affected versionversion=adf0398cee86643b8eacde95f17d073d022f782c <9dbd84990394c51f5cee1e8871bb5ff8af5ed939
- Affected versionversion=adf0398cee86643b8eacde95f17d073d022f782c <e8a5baff5be273ca07771fd2b9bb1f2a4152917b
- Affected versionversion=e137e2ba96e51902dc2878131823a96bf8e638ae
- Affected versionversion=e97e16433eb4533083b096a3824b93a5ca3aee79 <b5c59a5b469e2a809a2d57eda4ded94235971060
- Affected versionversion=eb86f955488c39526534211f2610e48a5cf8ead4
What conditions does exploitation require?
What is affected?
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
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
No sourced classifications are available.
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
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo