{"cve":"CVE-2026-63818","nvd":{"published":"2026-07-19T12:16:54.873","modified":"2026-08-17T05:17:19.143","status":"Awaiting Analysis","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: validate orphan inode entry count\n\nf2fs_recover_orphan_inodes() trusts the orphan block entry_count when\nreplaying orphan inodes from the checkpoint pack. A corrupted entry_count\nlarger than F2FS_ORPHANS_PER_BLOCK makes the recovery loop read past the\nino[] array and interpret footer or following data as inode numbers.\n\nOn a crafted image, mounting an unpatched kernel can drive orphan recovery\ninto f2fs_bug_on() and panic the kernel. Validate entry_count before\nconsuming entries so corrupted checkpoint data fails the mount with\n-EFSCORRUPTED and requests fsck instead.\n\nSet ERROR_INCONSISTENT_ORPHAN as well, so the corruption reason can be\nrecorded in the superblock s_errors[] field. This gives fsck a persistent\nhint even though mount-time orphan recovery failure may leave no chance to\npersist SBI_NEED_FSCK through a checkpoint.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","score":8.4},"cwes":[],"references":["https://git.kernel.org/stable/c/210c210c92d78fdf5051bc55c5c69044b1a2150a","https://git.kernel.org/stable/c/2e12381d4495dc8b0ff042c6856022b2e359835c","https://git.kernel.org/stable/c/550511a2470f6d204fa07b331f048bd2d3c51280","https://git.kernel.org/stable/c/846c499a65816d13f1186e3090e825e8bb8bcb8b","https://git.kernel.org/stable/c/8aad54746c251f2c2370118df766c0c82e2d2091"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:45:36.895656543+00:00"},"epss":{"cve":"CVE-2026-63818","score":0.0014,"percentile":0.0332,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}