Out-of-bounds write in Linux kernel - CVE-2026-74752

Vulnerability identifier: #VU145975

CSH Severity: High

CVSS v4: 9.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-74752

CWE-ID: CWE-787

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to execute arbitrary code.

The vulnerability exists due to an out-of-bounds write in SCTP COOKIE_ECHO handling when processing peer-controlled cookie AUTH fields with cookie authentication disabled. A remote attacker can send a forged cookie with a crafted HMAC identifier to execute arbitrary code.

The issue is reachable when cookie authentication is disabled, and malformed AUTH parameters restored from the cookie are not validated against local backing arrays.

Linux kernel
openEuler
kernel
bpftool
bpftool-debuginfo
kernel-debuginfo
kernel-debugsource
kernel-devel
kernel-headers
kernel-source
kernel-tools
kernel-tools-debuginfo
kernel-tools-devel
perf
perf-debuginfo
python3-perf
python3-perf-debuginfo

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
kernel - update to 5.10.0-334.0.0.235
bpftool - update to 5.10.0-334.0.0.235
bpftool-debuginfo - update to 5.10.0-334.0.0.235
kernel-debuginfo - update to 5.10.0-334.0.0.235
kernel-debugsource - update to 5.10.0-334.0.0.235
kernel-devel - update to 5.10.0-334.0.0.235
kernel-headers - update to 5.10.0-334.0.0.235
kernel-source - update to 5.10.0-334.0.0.235
kernel-tools - update to 5.10.0-334.0.0.235
kernel-tools-debuginfo - update to 5.10.0-334.0.0.235
kernel-tools-devel - update to 5.10.0-334.0.0.235
perf - update to 5.10.0-334.0.0.235
perf-debuginfo - update to 5.10.0-334.0.0.235
python3-perf - update to 5.10.0-334.0.0.235
python3-perf-debuginfo - update to 5.10.0-334.0.0.235

• https://git.kernel.org/stable/c/3dbb44d88b1e94dd31fe43588af7437b34b44d56
• https://git.kernel.org/stable/c/88619b117be1daf633ce32210570ce35a0bd1c98

• Out-of-bounds write in Linux kernel sctp
• openEuler 22.03 LTS SP4 update for kernel