What is CVE-2026-52909?

CVE-2026-52909 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10, affecting Linux kernel versions from 3.15 onward and patched in 5.10.260, 5.15.211, 6.1.177 and others. CVE-2026-52909 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-52909?

CVE-2026-52909 has a CVSS score of 7.8 out of 10, rated High severity. The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

Is there a patch available for CVE-2026-52909?

Yes, CVE-2026-52909 has been patched. Fixed versions include 5.10.260, 5.15.211, 6.1.177 and others. If you are running Linux kernel 3.15 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-52909 actively exploited?

CVE-2026-52909 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2026-52909

High

In the Linux kernel, the following vulnerability has been resolved: ip6_vti: set netns_immutable on the fallback device. john1988 and Noam Rathaus reported that vti6_init_net() does not set the netns_immutable flag on the per-netns fallback tunnel device (ip6_vti0). Other similar tunnel drivers (like ip6_tunnel, sit, ip6_gre, and ip_tunnel) correctly set this flag during their fallback device initialization to prevent them from being moved to another network namespace.

Package Linux Kernel

Published 2026-06-19

Last modified 2026-07-08

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

7.8

out of 10

High

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Vector string

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected versions

Linux kernel versions 3.15 and later are affected. Fixed in 5.10.260, 5.15.211, 6.1.177, 6.6.144, 6.12.95, 6.18.36, 7.0.13, 7.1 and their respective stable series.

Affected from

≥ 3.15

Fixed in

✓ 5.10.260 5.10.x ✓ 5.15.211 5.15.x ✓ 6.1.177 6.1.x ✓ 6.6.144 6.6.x ✓ 6.12.95 6.12.x ✓ 6.18.36 6.18.x ✓ 7.0.13 7.0.x ✓ 7.1

References

8 total

Kernel Git
https://git.kernel.org/stable/c/12acc977838c943636fb01e2f3087d2e4cc3b7cc

Patch
Kernel Git
https://git.kernel.org/stable/c/12c65e2c7fef507551bd7b52123598a761662c01

Patch
Kernel Git
https://git.kernel.org/stable/c/7f28e3948c59481f8db9c9638e204258d26b4e41

Patch
Kernel Git
https://git.kernel.org/stable/c/c5dbd669db5a426b3025512322e1bf2cdbe14305

Patch
Kernel Git
https://git.kernel.org/stable/c/d289d5307762d1838aaece22c6b6fcad9e8865f9

Patch

Showing 5 of 8 references View all on NVD

Details

CVE ID CVE-2026-52909

Severity High

CVSS score 7.8 / 10

CVSS version 3.1

Published 2026-06-19

Modified 2026-07-08

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2026-52909?

CVE-2026-52909 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10 . It affects Linux kernel versions from 3.15 onward and has been patched in 5.10.260, 5.15.211, 6.1.177 and others. CVE-2026-52909 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-52909?

CVE-2026-52909 has a CVSS score of 7.8 out of 10, rated High severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
Is there a patch available for CVE-2026-52909?

Yes. CVE-2026-52909 has been patched. Fixed versions include 5.10.260, 5.15.211, 6.1.177 and others. If you are running Linux kernel 3.15 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-52909 actively exploited?

No. CVE-2026-52909 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.