CVE-2026-63818

What it is

In the Linux kernel, the following vulnerability has been resolved: f2fs: validate orphan inode entry count f2fs_recover_orphan_inodes() trusts the orphan block entry_count when replaying orphan inodes from the checkpoint pack. A corrupted entry_count larger than F2FS_ORPHANS_PER_BLOCK makes the recovery loop read past the ino[] array and interpret footer or following data as inode numbers. On a crafted image, mounting an unpatched kernel can drive orphan recovery into f2fs_bug_on() and panic the kernel. Validate entry_count before consuming entries so corrupted checkpoint data fails the mount with -EFSCORRUPTED and requests fsck instead. Set ERROR_INCONSISTENT_ORPHAN as well, so the corruption reason can be recorded in the superblock s_errors[] field. This gives fsck a persistent hint even though mount-time orphan recovery failure may leave no chance to persist SBI_NEED_FSCK through a checkpoint.

At a glance

Exploitability

Can be exploited locally on the machine without logging in. High risk of data exposure, data tampering, service disruption.

Exploit odds

0.1% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-07-19 07:54 UTC ReservedThe CVE id was reserved by its CNA
2. 2026-07-19 12:16 UTC PublishedDisclosed publicly on CVE.org and NVD
3. 2026-11-10 21:15 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.1% in the next 30 days (EPSS).
• Severity: 8.4 HIGH (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2026-07-19 12:16 UTC

Last modified

2026-11-10 21:15 UTC

Exploit probability

0.1% · EPSS, next 30 days

Weakness

CWE-125 · Out-of-bounds read

Record status

Analyzed

Affected

• Linux Kernel < 5.10.261
• Linux Kernel < 5.15.212
• Linux Kernel < 6.1.178
• Linux Kernel < 6.6.145
• Linux Kernel < 6.12.96
• Linux Kernel < 6.18.38
• Linux Kernel < 7.1.3

Attack profile CVSS 3.1 · 8.4

Attack vector

Local

Complexity

Low

Privileges needed

None

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-63818.md and follow it. Check whether this project is affected by CVE-2026-63818. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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