Always-Incorrect Control Flow Implementation in Linux kernel - CVE-2026-63975

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Main Vulnerability Database Vulnerabilities #VU138677

Always-Incorrect Control Flow Implementation in Linux kernel - CVE-2026-63975

Published: July 20, 2026


Vulnerability identifier: #VU138677
CSH Severity: Medium
CVSS v4: 7.1 [CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-63975
CWE-ID: CWE-670
Exploitation vector: Adjecent network
Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to improper handling of channel deletion during list iteration in l2cap_ecred_conn_rsp in the Bluetooth L2CAP subsystem when processing a crafted L2CAP credit-based connection response with an already-assigned destination CID. A remote attacker can send a specially crafted Bluetooth packet to cause a denial of service.

The issue occurs when a duplicate destination CID is received for an L2CAP extended credit based connection response.


Affected software

Linux kernel
Red Hat CodeReady Linux Builder for ARM 64
Red Hat CodeReady Linux Builder for Power, little endian
Red Hat CodeReady Linux Builder for x86_64
Red Hat Enterprise Linux for ARM 64
Red Hat Enterprise Linux for Power, little endian
Red Hat Enterprise Linux for IBM z Systems
Red Hat Enterprise Linux for x86_64
Red Hat Enterprise Linux for Real Time
Red Hat Enterprise Linux for Real Time for NFV
Ubuntu
openEuler
kernel (Red Hat package)
kernel-rt (Red Hat package)
kernel
kernel-devel
bpftool
bpftool-debuginfo
kernel-debuginfo
kernel-debugsource
kernel-headers
kernel-source
kernel-tools
kernel-tools-debuginfo
kernel-tools-devel
perf
perf-debuginfo
python3-perf
python3-perf-debuginfo
kernel-extra-modules
linux (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-oracle-5.15 (Ubuntu package)
linux-gcp-5.15 (Ubuntu package)
linux-gcp (Ubuntu package)
linux-gke (Ubuntu package)
linux-nvidia-tegra (Ubuntu package)
linux-azure (Ubuntu package)
linux-ibm (Ubuntu package)
linux-aws (Ubuntu package)
linux-gcp-7.0 (Ubuntu package)
linux-oracle-7.0 (Ubuntu package)
linux-azure-7.0 (Ubuntu package)
linux-nvidia-bos (Ubuntu package)

How to mitigate CVE-2026-63975

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
kernel (Red Hat package) - update to 4.18.0-553.166.1.el8_10
kernel-rt (Red Hat package) - update to 4.18.0-553.166.1.rt7.507.el8_10
kernel - addressed in versions 5.10.0-327.0.0.228, 6.6.0-145.1.20.157, 6.6.0-145.3.29.160
kernel-devel - addressed in versions 5.10.0-327.0.0.228, 6.6.0-145.1.20.157, 6.6.0-145.3.29.160
bpftool - addressed in versions 5.10.0-327.0.0.228, 6.6.0-145.1.20.157, 6.6.0-145.3.29.160
bpftool-debuginfo - addressed in versions 5.10.0-327.0.0.228, 6.6.0-145.1.20.157, 6.6.0-145.3.29.160
kernel-debuginfo - addressed in versions 5.10.0-327.0.0.228, 6.6.0-145.1.20.157, 6.6.0-145.3.29.160
kernel-debugsource - addressed in versions 5.10.0-327.0.0.228, 6.6.0-145.1.20.157, 6.6.0-145.3.29.160
kernel-headers - addressed in versions 5.10.0-327.0.0.228, 6.6.0-145.1.20.157, 6.6.0-145.3.29.160
kernel-source - addressed in versions 5.10.0-327.0.0.228, 6.6.0-145.1.20.157, 6.6.0-145.3.29.160
kernel-tools - addressed in versions 5.10.0-327.0.0.228, 6.6.0-145.1.20.157, 6.6.0-145.3.29.160
kernel-tools-debuginfo - addressed in versions 5.10.0-327.0.0.228, 6.6.0-145.1.20.157, 6.6.0-145.3.29.160
kernel-tools-devel - addressed in versions 5.10.0-327.0.0.228, 6.6.0-145.1.20.157, 6.6.0-145.3.29.160
perf - addressed in versions 5.10.0-327.0.0.228, 6.6.0-145.1.20.157, 6.6.0-145.3.29.160
perf-debuginfo - addressed in versions 5.10.0-327.0.0.228, 6.6.0-145.1.20.157, 6.6.0-145.3.29.160
python3-perf - addressed in versions 5.10.0-327.0.0.228, 6.6.0-145.1.20.157, 6.6.0-145.3.29.160
python3-perf-debuginfo - addressed in versions 5.10.0-327.0.0.228, 6.6.0-145.1.20.157, 6.6.0-145.3.29.160
kernel-extra-modules - update to 6.6.0-145.3.29.160
linux (Ubuntu package) - addressed in versions 5.15.0-195.205~20.04.1, 5.15.0-195.205, 5.15.0-198.208~20.04.1, 5.15.0-198.208+fips1, 5.15.0-1080.84, 5.15.0-1100.108, 5.15.0-1109.111, 5.15.0-1109.114, 5.15.0-1111.115~20.04.1, 5.15.0-1111.115, 5.15.0-1112.118~20.04.1, 5.15.0-1112.118, 5.15.0-1113.119, 5.15.0-1114.120, 5.15.0-1116.125~20.04.1, 5.15.0-1117.124~20.04.1, 5.15.0-1117.124, 5.15.0-1117.124+fips1, 5.15.0-1122.131~20.04.1, 5.15.0-1123.132~20.04.1, 5.15.0-1123.132, 5.15.0-1123.132+fips1, 5.15.0.195.160, 5.15.0.195.205~20.04.1, 5.15.0.198.114, 5.15.0.198.171, 5.15.0.198.208~20.04.1, 5.15.0.1080.83~20.04.1, 5.15.0.1100.99, 5.15.0.1109.105, 5.15.0.1109.113, 5.15.0.1111.108, 5.15.0.1111.115~20.04.1, 5.15.0.1112.111, 5.15.0.1112.118~20.04.1, 5.15.0.1113.112, 5.15.0.1114.110, 5.15.0.1116.120, 5.15.0.1117.113, 5.15.0.1117.120, 5.15.0.1117.124~20.04.1, 5.15.0.1122.131~20.04.1, 5.15.0.1123.107, 5.15.0.1123.121, 5.15.0.1123.132~20.04.1
linux-nvidia (Ubuntu package) - addressed in versions 5.15.0-1112.113, 5.15.0.1112.112, 7.0.0-1016.16~24.04.1, 7.0.0-1016.16
linux-oracle-5.15 (Ubuntu package) - addressed in versions 5.15.0-1114.120~20.04.1, 5.15.0.1114.120~20.04.1
linux-gcp-5.15 (Ubuntu package) - addressed in versions 5.15.0-1118.128~20.04.1, 5.15.0.1118.128~20.04.1
linux-gcp (Ubuntu package) - addressed in versions 5.15.0-1118.128, 5.15.0-1118.128+fips1, 5.15.0.1118.107, 5.15.0.1118.115, 6.8.0-1070.78
linux-gke (Ubuntu package) - addressed in versions 6.8.0-146.146.1~22.04.1, 6.8.0-146.146.1, 6.8.0-1051.55, 6.8.0-1063.66, 6.8.0-1064.67~22.04.1, 6.8.0-1064.67, 6.8.0-1064.67.1, 6.8.0-1065.73, 6.8.0-1066.67
linux-nvidia-tegra (Ubuntu package) - update to 6.8.0-1035.38
linux-azure (Ubuntu package) - addressed in versions 6.8.0-1068.75~22.04.1, 6.8.0-1068.75, 6.8.0-1069.77+fips1, 6.8.0-1070.78~22.04.1, 6.8.0-1070.78, 7.0.0-1009.9, 7.0.0-1010.10
linux-ibm (Ubuntu package) - addressed in versions 7.0.0-1008.8, 7.0.0-1010.10
linux-aws (Ubuntu package) - addressed in versions 7.0.0-1009.9, 7.0.0-1015.15
linux-gcp-7.0 (Ubuntu package) - update to 7.0.0-1011.11~24.04.1
linux-oracle-7.0 (Ubuntu package) - update to 7.0.0-1011.11~24.04.1
linux-azure-7.0 (Ubuntu package) - update to 7.0.0-1014.14~24.04.1
linux-nvidia-bos (Ubuntu package) - update to 7.0.0-2016.16

External References

Related Security Bulletins