CVE-2026-89569: Linux kernel · Bluetooth: RFCOMM: serialize security confirmation handling
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 8.8 High.
Data as of 26 Oct 2026, 12:55 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 27% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
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 11 Sep 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 26.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-azure-fdepkg:deb/ubuntu/linux-azure-fde?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=resoluteOther 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 fix is available that serializes access in rfcomm_security_cfm() by holding rfcomm_mutex during session lookup and DLC traversal. Users should apply the official Linux kernel patches that address this concurrency issue. Since this is a kernel-level vulnerability, updating to a patched kernel version is the recommended remediation.
Description
A use-after-free vulnerability in the Linux kernel's Bluetooth RFCOMM implementation was resolved. The flaw occurs because rfcomm_security_cfm() accesses session and DLC objects without holding the rfcomm_mutex, allowing concurrent teardown and freeing of these objects. This can lead to reading freed memory and potential system instability or compromise. The issue was detected by KASAN and affects specific Linux kernel versions. The vulnerability has a CVSS score of 8.8, indicating high severity.
References
- nvd.nist.gov/vuln/detail/CVE-2026-89569 (opens in a new tab)
- git.kernel.org/stable/c/1b7841ffad08e911e8c4b9470f3fa08423568940 (opens in a new tab)
- git.kernel.org/stable/c/759c185d0bbdb131357408f50b8735e04ed3caff (opens in a new tab)
- git.kernel.org/stable/c/946d76db77ee5f922968ce558629ae47b381e3fc (opens in a new tab)
- git.kernel.org/stable/c/fbf7961964a6e93360179f64712320ae9a1e9577 (opens in a new tab)
- ubuntu.com/security/CVE-2026-89569 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-89569 (opens in a new tab)
- git.kernel.org/linus/759c185d0bbdb131357408f50b8735e04ed3caff (opens in a new tab)
- msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-89569.json (opens in a new tab)
- support.microsoft.com/lifecycle (opens in a new tab)
- first.org/cvss (opens in a new tab)