Skip to main content

Linux Kernel CVE-2026-64002

| EUVDEUVD-2026-45575 HIGH
2026-07-19 Linux GHSA-gghq-r38g-rg55
7.8
CVSS 3.1 · Vendor: Linux
Share

Severity by source

Vendor (Linux) PRIMARY
7.8 HIGH
AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
vuln.today AI
7.0 HIGH

Local access and low privileges suffice (AV:L/PR:L), but triggering the teardown use-after-free is a timing race (AC:H); kernel memory corruption yields high C/I/A.

3.1 AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
4.0 AV:L/AC:H/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
SUSE
HIGH
qualitative
Red Hat
7.0 MEDIUM
qualitative

Primary rating from Vendor (Linux).

CVSS VectorVendor: Linux

Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

Lifecycle Timeline

5
Analysis Generated
Jul 20, 2026 - 16:45 vuln.today
CVSS changed
Jul 20, 2026 - 15:22 NVD
7.8 (HIGH)
Patch available
Jul 19, 2026 - 17:19 EUVD
CVE Published
Jul 19, 2026 - 14:56 cve.org
HIGH 7.8
CVE Published
Jul 19, 2026 - 14:56 cve.org
UNKNOWN (no severity yet)

DescriptionCVE.org

In the Linux kernel, the following vulnerability has been resolved:

ipv4: free net->ipv4.sysctl_local_reserved_ports after unregister_net_sysctl_table()

ipv4_sysctl_exit_net() is currently freeing net->ipv4.sysctl_local_reserved_ports too soon.

Only after unregister_net_sysctl_table() we can be sure no threads can possibly use the sysctls, including /proc/sys/net/ipv4/ip_local_reserved_ports.

AnalysisAI

Use-after-free in the Linux kernel's IPv4 sysctl teardown path (ipv4_sysctl_exit_net) can corrupt kernel memory because net->ipv4.sysctl_local_reserved_ports is freed before unregister_net_sysctl_table(), leaving a window where threads accessing /proc/sys/net/ipv4/ip_local_reserved_ports reference freed memory. A local low-privileged attacker able to trigger network namespace teardown could leverage the dangling pointer for memory corruption, information disclosure, or potential privilege escalation. No public exploit identified at time of analysis; EPSS is low (0.18%, 7th percentile) and the issue is not on CISA KEV, consistent with a fix delivered quietly through the kernel stable process.

Technical ContextAI

The affected component is the IPv4 sysctl handling in the Linux networking stack, specifically the per-network-namespace lifecycle managed by ipv4_sysctl_exit_net(). The kernel exposes tunables such as ip_local_reserved_ports via /proc/sys/net/ipv4/, backed by a dynamically allocated bitmap (sysctl_local_reserved_ports). The root cause is an ordering bug: the code kfree()s the reserved-ports allocation before calling unregister_net_sysctl_table(), so the sysctl entry remains reachable to other threads after its backing store has been released. This is a classic use-after-free (CWE-416) driven by incorrect teardown sequencing during netns cleanup - the guarantee that no thread can reach the sysctl only holds after unregistration completes. The CWE was listed as N/A in the feed, but the description ('free ... too soon') and the fix (reordering the free after unregister) are textbook UAF. Affected CPE is cpe:2.3:a:linux:linux, i.e. the mainline/stable kernel across many branches back to 3.16.

RemediationAI

Vendor-released patch: update to a fixed stable kernel - 5.10.259, 5.15.210, 6.1.176, 6.6.143, 6.12.93, 6.18.35, 7.0.12, or 7.1 (or later on your branch), or the distribution kernel that backports the corresponding stable commit (e.g. https://git.kernel.org/stable/c/ecf45080a4d3f4526cacb8b14060fe3b49a6913b). On managed distributions, apply the vendor kernel errata and reboot, since a running kernel remains vulnerable until replaced; live-patching may not cover a teardown-ordering fix, so verify with the vendor. Where immediate patching is not possible, reduce the attack surface that lets unprivileged users trigger network-namespace teardown: set kernel.unprivileged_userns_clone=0 (or sysctl user.max_user_namespaces=0) to block unprivileged netns creation - note this can break container runtimes, sandboxed browsers, and CI tooling that rely on user namespaces. Restricting who can create namespaces (seccomp/AppArmor profiles limiting clone/unshare, or confining workloads to trusted tenants) is a lower-collateral alternative but does not eliminate the race for privileged or authorized namespace users.

Vendor StatusVendor

SUSE

Severity: Important
Product Status
SUSE Linux Enterprise Desktop 15 SP7 Affected
SUSE Linux Enterprise Desktop 15 SP7 Affected
SUSE Linux Enterprise High Availability Extension 15 SP7 Affected
SUSE Linux Enterprise High Availability Extension 15 SP7 Affected
SUSE Linux Enterprise High Availability Extension 16.0 Affected

Share

CVE-2026-64002 vulnerability details – vuln.today

This site uses cookies essential for authentication and security. No tracking or analytics cookies are used. Privacy Policy