Out-of-bounds read in Linux kernel - CVE-2026-74569

Vulnerability identifier: #VU143200

CSH Severity: Medium

CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-74569

CWE-ID: CWE-125

Exploitation vector: Remote access

Exploit availability: No public exploit available

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

The vulnerability exists due to an out-of-bounds read in ct_sip_get_header() in the nf_conntrack_sip SIP connection-tracking helper when processing NAT-rewritten SIP messages over TCP. A remote attacker can send a specially crafted SIP message with a long Contact list to cause a denial of service.

The issue is triggered by integer wraparound in size-change tracking during repeated URI rewriting, which can produce an invalid length value for a subsequent header parse.

Linux kernel
Debian Linux
Red Hat CodeReady Linux Builder for ARM 64
Red Hat Enterprise Linux for Real Time
Red Hat Enterprise Linux for Real Time for NFV
Red Hat Enterprise Linux for x86_64
Red Hat Enterprise Linux for IBM z Systems
Red Hat Enterprise Linux for Power, little endian
Red Hat Enterprise Linux for ARM 64
Red Hat CodeReady Linux Builder for x86_64
Red Hat CodeReady Linux Builder for Power, little endian
Ubuntu
kernel (Red Hat package)
kernel-rt (Red Hat package)
linux-nvidia-tegra (Ubuntu package)
kernel-zfcpdump-devel-matched (Red Hat package)
kernel-64k-devel-matched (Red Hat package)
kernel-64k-devel (Red Hat package)
kernel-64k-debug-devel-matched (Red Hat package)
kernel-64k-debug-devel (Red Hat package)
kernel-zfcpdump-devel (Red Hat package)
python3-perf (Red Hat package)
perf (Red Hat package)
kernel-headers (Red Hat package)
kernel-devel-matched (Red Hat package)
kernel-devel (Red Hat package)
kernel-debug-devel-matched (Red Hat package)
kernel-debug-devel (Red Hat package)
linux (Debian package)

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
kernel (Red Hat package) - addressed in versions 4.18.0-553.171.1.el8_10, 5.14.0-687.55.1.el9_8
kernel-rt (Red Hat package) - update to 4.18.0-553.171.1.rt7.512.el8_10
linux-nvidia-tegra (Ubuntu package) - update to 6.8.0-1035.38
kernel-zfcpdump-devel-matched (Red Hat package) - update to 6.12.0-211.59.1.el10_2
kernel-64k-devel-matched (Red Hat package) - update to 6.12.0-211.59.1.el10_2
kernel-64k-devel (Red Hat package) - update to 6.12.0-211.59.1.el10_2
kernel-64k-debug-devel-matched (Red Hat package) - update to 6.12.0-211.59.1.el10_2
kernel-64k-debug-devel (Red Hat package) - update to 6.12.0-211.59.1.el10_2
kernel-zfcpdump-devel (Red Hat package) - update to 6.12.0-211.59.1.el10_2
python3-perf (Red Hat package) - update to 6.12.0-211.59.1.el10_2
perf (Red Hat package) - update to 6.12.0-211.59.1.el10_2
kernel-headers (Red Hat package) - update to 6.12.0-211.59.1.el10_2
kernel-devel-matched (Red Hat package) - update to 6.12.0-211.59.1.el10_2
kernel-devel (Red Hat package) - update to 6.12.0-211.59.1.el10_2
kernel-debug-devel-matched (Red Hat package) - update to 6.12.0-211.59.1.el10_2
kernel-debug-devel (Red Hat package) - update to 6.12.0-211.59.1.el10_2
linux (Debian package) - update to 6.12.105-1

• https://git.kernel.org/stable/c/63eea41759fd682229c14e0a2205802b46d106f3
• https://git.kernel.org/stable/c/c97621a110e386b2dd69e276eb699e1d3cec581d
• https://git.kernel.org/stable/c/db3d0e0e5d4bc5ab4fe445b9f413d1b486508ca5
• https://git.kernel.org/stable/c/ef5e2c6555d2bb52dfe0e4053a8c6193f9d83b64
• https://git.kernel.org/stable/c/f74554e67ccf04d1fa71069e8c9afa2717e40716

• Out-of-bounds read in Linux kernel netfilter
• Debian update for linux
• Red Hat Enterprise Linux 10 update for kernel
• Ubuntu update for linux-nvidia-tegra
• Red Hat Enterprise Linux 8 update for kernel-rt
• Red Hat Enterprise Linux 8 update for kernel
• Red Hat Enterprise Linux 9 update for kernel