CVE-2026-99009: Linux kernel · Bluetooth: RFCOMM: connect the session socket without rfcomm_mutex
Affects Linux kernelSource CVE Database V5
Not known to be exploited · fixed in f492de11b325446b0b11bc2eb86e1f546eaa61b6 : update Linux kernel when convenient.
Data as of 26 Oct 2026, 13:07 UTC
Rated Medium by Threat Radar's AI analysis · CVSS not yet scored by NVD
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 6% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in f492de11b325446b0b11bc2eb86e1f546eaa61b6, d2206e8c78be69d21d4f5343c3e99fbaeef41cbb, cc7732b8549ecb6f02457edeb8db1f6d255e381c +9
Exploitation evidence
Disclosed: evidence found.
CVE published 23 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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AI-suggested
A fix is available and has been applied in Linux kernel versions 5.11, 5.16, 6.2, 6.18.58, and 7.2.11 and later. Users and administrators should upgrade to these or later kernel versions to remediate the issue. No additional mitigation actions are indicated by the vendor advisory.
Description
CVE-2026-99009 is a vulnerability in the Linux kernel's Bluetooth RFCOMM implementation involving improper locking order during session socket connection. This flaw causes a circular locking dependency between rfcomm_mutex and hdev->lock, leading to lockdep warnings and potential deadlocks. The issue arises when an RFCOMM connect() call is made while a BR/EDR link is being authenticated. The fix involves changing the locking order to connect the session socket before acquiring rfcomm_mutex, preventing the circular dependency and ensuring proper session management.
References
- git.kernel.org/stable/c/4dc3d5a004b8fd59f3c905631dbb18cb601b1b41 (opens in a new tab)
- git.kernel.org/stable/c/d2206e8c78be69d21d4f5343c3e99fbaeef41cbb (opens in a new tab)
- git.kernel.org/stable/c/cc7732b8549ecb6f02457edeb8db1f6d255e381c (opens in a new tab)
- git.kernel.org/stable/c/f492de11b325446b0b11bc2eb86e1f546eaa61b6 (opens in a new tab)
- git.kernel.org/stable/c/ac022970e9fb0a5f7e7d1f6c8e104c1ed924dd1c (opens in a new tab)