CVE-2026-64206 — Bluetooth: L2CAP: cancel pending_rx_work before taking conn->lock
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: cancel pending_rx_work before taking conn->lock l2cap_conn_del() takes conn->lock and then calls cancel_work_sync() for pending_rx_work. process_pending_rx() takes the same mutex, so teardown can deadlock against the worker it is flushing. This issue was found by our static analysis tool and then manually reviewed against the current tree. The grounded PoC kept the l2cap_conn_ready() -> queue_work(..., &conn->pending_rx_work) submit path, the l2cap_conn_del() -> cancel_work_sync(&conn->pending_rx_work) teardown path, and the process_pending_rx() -> mutex_lock(&conn->lock) worker edge. Lockdep WARNING: possible circular locking dependency detected process_pending_rx+0x21/0x2a [vuln_msv] l2cap_conn_del.constprop.0+0x3f/0x4e [vuln_msv] *** DEADLOCK *** Cancel pending_rx_work before taking conn->lock, matching the existing lock-before-drain ordering used for the two delayed works in the same teardown path. The pending_rx queue is still purged after the work has been cancelled and conn->lock has been acquired.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- Technical severity (high)+6
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Linux Linux, Linux Linux Kernel).
- Apply the fixed version or the patch documented under Remediation.
- Search available logs for exploit probes, errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Linux | Linux |
version 3.16≥ 3.15.5 and < 3.16version ee805f9499ebd0edf0877990968543c752043b59≥ 7ab56c3a6eccb215034b0cb096e0313441cbf2a4 and < 2641a9e0a1dd4af2e21995470a21d55dd35e5203≥ 7ab56c3a6eccb215034b0cb096e0313441cbf2a4 and < e96fbac8d3a73b0bc165383c092a30628561d320≥ 7ab56c3a6eccb215034b0cb096e0313441cbf2a4 and < d5616beb3355b5fca2280d796c1cf7ada4ee6551≥ 7ab56c3a6eccb215034b0cb096e0313441cbf2a4 and < 8de7b386ffad480ca59222b688c94a2da8f0d805≥ 7ab56c3a6eccb215034b0cb096e0313441cbf2a4 and < 8daaf7f73fe998631a160d1a5a7e1b0b0480eef8 and 3 more≥ 7ab56c3a6eccb215034b0cb096e0313441cbf2a4 and < 4a0bb0fd63fe2b0c62e1072cd1811d6f61e0081c≥ 7ab56c3a6eccb215034b0cb096e0313441cbf2a4 and < 9901f847a762a5d953871dd95767ce2aed3d684d≥ 7ab56c3a6eccb215034b0cb096e0313441cbf2a4 and < fc0c3b9cf27cfa2a06f66dae1d08c668fe0a2faa |
Vulnerable | CVE Program (cve.org) e CISA ADP |
| Linux | Linux Kernel |
version 3.16-rc7version 7.2-rc2version 7.2-rc1≥ 3.15.5 and < 3.16version 3.16-rc6version 3.16-rc5version 3.16-rc4version 3.16-rc3 and 8 moreversion 3.16≥ 6.19 and < 7.1.4≥ 6.13 and < 6.18.39≥ 6.7 and < 6.12.97≥ 6.2 and < 6.6.145≥ 5.16 and < 6.1.178≥ 5.11 and < 5.15.212≥ 3.16.1 and < 5.10.261 |
Vulnerable | NIST National Vulnerability Database |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 8.8 | CVSS 3.1 | High | 2.8 | 5.9 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 via NIST National Vulnerability Database |
| 8.8 | CVSS 3.1 | High | — | — | Linux via CVE Program (cve.org) e CISA ADP |
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H (score shown at the top: 416baaa9-dc9f-4396-8d5f-8c081fb06d67) Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Not enough vector or weakness data: use the affected application’s logs as a starting point.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · linux/linux
- Record published
- Fix documented
- CVSS changed · 8.8
- Source status changed · → Analyzed
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 15, 2026 – Oct 15, 2026
References
8 on the record
- git.kernel.org/stable/c/9901f847a762a5d953871dd95767ce2aed3d684d
- git.kernel.org/stable/c/8daaf7f73fe998631a160d1a5a7e1b0b0480eef8
- git.kernel.org/stable/c/2641a9e0a1dd4af2e21995470a21d55dd35e5203
- git.kernel.org/stable/c/e96fbac8d3a73b0bc165383c092a30628561d320
- git.kernel.org/stable/c/8de7b386ffad480ca59222b688c94a2da8f0d805
- git.kernel.org/stable/c/d5616beb3355b5fca2280d796c1cf7ada4ee6551
- git.kernel.org/stable/c/4a0bb0fd63fe2b0c62e1072cd1811d6f61e0081c
- git.kernel.org/stable/c/fc0c3b9cf27cfa2a06f66dae1d08c668fe0a2faa
Elsewhere on this site
Related CVEs (same products)
- Critical CVE-2026-99999 ipv4: validate checksum_start before completing checksum 11h
- Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 11h
- Unknown CVE-2026-98424 wifi: cfg80211: undo netns switch if renaming the wiphy fails 1d
- Unknown CVE-2026-98425 wifi: mac80211: don't warn when an IBSS has no channel to scan 1d
- Unknown CVE-2026-98426 wifi: mwifiex: fix IRQ leak using wrong index in MSI-X error path 1d
- Unknown CVE-2026-98427 net/sched: codel: bound the dropping loop per dequeue call 1d
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No FIRST EPSS score.
- No CISA SSVC assessment.
- No CWE classification.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2026-64206 is "Bluetooth: L2CAP: cancel pending_rx_work before taking conn->lock", rated High. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 8.8 describes technical severity. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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