What is CVE-2026-63817?

CVE-2026-63817 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10, affecting Linux kernel versions from 5.13.19 onward and patched in 5.15.212, 6.1.177, 6.6.144 and others. CVE-2026-63817 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-63817?

CVE-2026-63817 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-2026-63817?

Yes, CVE-2026-63817 has been patched. Fixed versions include 5.15.212, 6.1.177, 6.6.144 and others. If you are running Linux kernel 5.13.19 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-63817 actively exploited?

CVE-2026-63817 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2026-63817

High

In the Linux kernel, the following vulnerability has been resolved: f2fs: validate compress cache inode only when enabled F2FS_COMPRESS_INO() uses NM_I(sbi)->max_nid as the synthetic inode number for the compressed page cache inode. That inode only exists when the compress_cache mount option is enabled. When compress_cache is disabled, max_nid is outside the valid inode range. A corrupted directory entry that points to ino == max_nid should therefore be rejected by f2fs_check_nid_range(). However, is_meta_ino() currently treats F2FS_COMPRESS_INO() as a meta inode unconditionally, so f2fs_iget() bypasses do_read_inode() and its nid range check, and instantiates a fake internal inode instead. Gate the compressed cache inode case on COMPRESS_CACHE, matching f2fs_init_compress_inode(). With compress_cache disabled, ino == max_nid now follows the normal inode path and is rejected as an out-of-range nid.

Package Linux Kernel

Published 2026-07-19

Last modified 2026-08-17

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 5.13.19, 5.14 and later are affected. Fixed in 5.15.212, 6.1.177, 6.6.144, 6.12.95, 6.18.38, 7.1.3, 7.2 and their respective stable series.

Affected from

≥ 5.13.19 ≥ 5.14

Fixed in

✓ 5.15.212 5.15.x ✓ 6.1.177 6.1.x ✓ 6.6.144 6.6.x ✓ 6.12.95 6.12.x ✓ 6.18.38 6.18.x ✓ 7.1.3 7.1.x ✓ 7.2

References

7 total

Showing 5 of 7 references View all on NVD

Details

CVE ID CVE-2026-63817

Severity High

CVSS score 7.8 / 10

CVSS version 3.1

Published 2026-07-19

Modified 2026-08-17

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2026-63817?

CVE-2026-63817 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10 . It affects Linux kernel versions from 5.13.19 onward and has been patched in 5.15.212, 6.1.177, 6.6.144 and others. CVE-2026-63817 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-63817?

CVE-2026-63817 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-2026-63817?

Yes. CVE-2026-63817 has been patched. Fixed versions include 5.15.212, 6.1.177, 6.6.144 and others. If you are running Linux kernel 5.13.19 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-63817 actively exploited?

No. CVE-2026-63817 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.