CVE-2026-31408: Linux kernel · Bluetooth: SCO: Fix use-after-free in sco_recv_frame() due to missing sock_hold
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 8.8 High · patch available : patch Linux kernel soon.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 23% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 6 Apr 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
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 25.10linuxpkg:deb/ubuntu/linux@6.17.0-40.40?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-awspkg:deb/ubuntu/linux-aws@6.17.0-1019.19?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-azurepkg:deb/ubuntu/linux-azure@6.17.0-1020.20?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-azure-fdepkg:deb/ubuntu/linux-azure-fde@6.17.0-1017.17?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-gcppkg:deb/ubuntu/linux-gcp@6.17.0-1020.22?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Ubuntu 25.10linux-oraclepkg:deb/ubuntu/linux-oracle@6.17.0-1018.18?arch=source&distro=questingOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
A patch is available and should be applied promptly. The vendor advisory from Ubuntu confirms that this issue has been fixed in updated Linux kernel packages. Users should update to the fixed kernel versions provided by their distribution to mitigate this vulnerability.
Description
A use-after-free vulnerability in the Linux kernel Bluetooth SCO subsystem was fixed. The flaw occurred in the sco_recv_frame() function, where a socket reference was not properly held before releasing a lock, allowing a concurrent close() to free the socket and cause a use-after-free. This could lead to system compromise. The issue affects specific Linux kernel versions and has a CVSS score of 8.8. A patch is available and has been released by vendors including Ubuntu.
References
- ubuntu.com/security/CVE-2026-31408 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-31408 (opens in a new tab)
- git.kernel.org/linus/598dbba9919c5e36c54fe1709b557d64120cb94b (opens in a new tab)
- git.kernel.org/stable/c/108b81514d8f2535eb16651495cefb2250528db3 (opens in a new tab)
- git.kernel.org/stable/c/45aaca995e4a7a05b272a58e7ab2fff4f611b8f1 (opens in a new tab)
- git.kernel.org/stable/c/598dbba9919c5e36c54fe1709b557d64120cb94b (opens in a new tab)
- git.kernel.org/stable/c/7197462e90b8ce15caa1ae15d4bc2bb8cd21b11e (opens in a new tab)
- git.kernel.org/stable/c/e76e8f0581ef555eacc11dbb095e602fb30a5361 (opens in a new tab)
- ubuntu.com/security/notices/USN-8567-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8574-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8575-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8576-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8574-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8595-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8596-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8575-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8576-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8597-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-8595-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-8606-1 (opens in a new tab)