8.4
HIGH
CVSS 3.1
CVE-2026-63815
f2fs: bound i_inline_xattr_size for non-inline-xattr inodes
Overview
Description
In the Linux kernel, the following vulnerability has been resolved: f2fs: bound i_inline_xattr_size for non-inline-xattr inodes When the flexible_inline_xattr feature is enabled, do_read_inode() loads the on-disk i_inline_xattr_size unconditionally: if (f2fs_sb_has_flexible_inline_xattr(sbi)) fi->i_inline_xattr_size = le16_to_cpu(ri->i_inline_xattr_size); but sanity_check_inode() only range-checks it when the inode also has the FI_INLINE_XATTR flag set. An inode that carries an inline dentry or inline data but not FI_INLINE_XATTR -- the normal layout for an inline directory -- therefore keeps a fully attacker-controlled i_inline_xattr_size from a crafted image. get_inline_xattr_addrs() returns that value with no flag gating, so it feeds the inode geometry: MAX_INLINE_DATA() = 4 * (CUR_ADDRS_PER_INODE - i_inline_xattr_size - 1) NR_INLINE_DENTRY() = MAX_INLINE_DATA() * BITS_PER_BYTE / (...) addrs_per_page() = CUR_ADDRS_PER_INODE - i_inline_xattr_size A large i_inline_xattr_size drives MAX_INLINE_DATA() and NR_INLINE_DENTRY() negative, so make_dentry_ptr_inline() sets d->max (int) to a negative value. The inline directory walk then compares an unsigned long bit_pos against that negative d->max, which is promoted to a huge unsigned bound, and reads far past the inline area: while (bit_pos < d->max) /* fs/f2fs/dir.c */ ... test_bit_le(bit_pos, d->bitmap) / d->dentry[bit_pos] ... Mounting a crafted image and reading such a directory triggers an out-of-bounds read in f2fs_fill_dentries(); the same underflow also corrupts ADDRS_PER_INODE for regular files. Validate i_inline_xattr_size against MAX_INLINE_XATTR_SIZE whenever the flexible_inline_xattr feature is enabled -- i.e. whenever the value is loaded from disk and consumed -- and keep the lower MIN_INLINE_XATTR_SIZE bound gated on inodes that actually carry an inline xattr, so legitimate inodes with i_inline_xattr_size == 0 are still accepted.
Details
INFO
Published Date :
July 19, 2026, 12:16 p.m.
Last Modified :
Aug. 17, 2026, 5:17 a.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Scoring
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework
for assessing the severity of vulnerabilities in software and systems.
We collect and displays CVSS scores from various sources for each CVE.
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
Solution
Apply Linux kernel updates to fix out-of-bounds read vulnerabilities.
- Update the Linux kernel.
- Validate i_inline_xattr_size on load.
- Bound size checks for inline attributes.
- Verify directory and file structures.
References
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-63815.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-63815 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-63815
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-63815 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-63815 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Aug. 17, 2026
Action Type Old Value New Value Changed Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '6afc662e68b5f988282ff20afd58a89b1c279dca', 'lessThan': '3c8d6b4093aea40a20596f452289e7c22d84e6d5', 'versionType': 'git'}, {'status': 'affected', 'version': '6afc662e68b5f988282ff20afd58a89b1c279dca', 'lessThan': 'a08ee30dcbeff6b97df75c38c2589603ddde53a6', 'versionType': 'git'}, {'status': 'affected', 'version': '6afc662e68b5f988282ff20afd58a89b1c279dca', 'lessThan': 'c3e05522daae4e7348a1ea81eeb321d25aa0fd3b', 'versionType': 'git'}, {'status': 'affected', 'version': '6afc662e68b5f988282ff20afd58a89b1c279dca', 'lessThan': '76e1a05cf6d4051931d7fa4ead51a05786a62918', 'versionType': 'git'}, {'status': 'affected', 'version': '6afc662e68b5f988282ff20afd58a89b1c279dca', 'lessThan': '2a9f9791653ba5ed3fb45bbffa8d63a7cd5cf706', 'versionType': 'git'}, {'status': 'affected', 'version': '6afc662e68b5f988282ff20afd58a89b1c279dca', 'lessThan': '4ce2d52f680c1d8bfdad7cce05b815ea7ca9790d', 'versionType': 'git'}, {'status': 'affected', 'version': '6afc662e68b5f988282ff20afd58a89b1c279dca', 'lessThan': '16bc237ce3c483b75575abea53cfb639745311ed', 'versionType': 'git'}, {'status': 'affected', 'version': '6afc662e68b5f988282ff20afd58a89b1c279dca', 'lessThan': '378acf3cf19b6af6cba55e8dd1154c4e1504bae8', 'versionType': 'git'}], 'programFiles': ['fs/f2fs/inode.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '4.15'}, {'status': 'unaffected', 'version': '0', 'lessThan': '4.15', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '5.10.261', 'versionType': 'semver', 'lessThanOrEqual': '5.10.*'}, {'status': 'unaffected', 'version': '5.15.212', 'versionType': 'semver', 'lessThanOrEqual': '5.15.*'}, {'status': 'unaffected', 'version': '6.1.178', 'versionType': 'semver', 'lessThanOrEqual': '6.1.*'}, {'status': 'unaffected', 'version': '6.6.145', 'versionType': 'semver', 'lessThanOrEqual': '6.6.*'}, {'status': 'unaffected', 'version': '6.12.96', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.39', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.3', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2-rc1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['fs/f2fs/inode.c'], 'defaultStatus': 'affected'}] [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '6afc662e68b5f988282ff20afd58a89b1c279dca', 'lessThan': '3c8d6b4093aea40a20596f452289e7c22d84e6d5', 'versionType': 'git'}, {'status': 'affected', 'version': '6afc662e68b5f988282ff20afd58a89b1c279dca', 'lessThan': 'a08ee30dcbeff6b97df75c38c2589603ddde53a6', 'versionType': 'git'}, {'status': 'affected', 'version': '6afc662e68b5f988282ff20afd58a89b1c279dca', 'lessThan': 'c3e05522daae4e7348a1ea81eeb321d25aa0fd3b', 'versionType': 'git'}, {'status': 'affected', 'version': '6afc662e68b5f988282ff20afd58a89b1c279dca', 'lessThan': '76e1a05cf6d4051931d7fa4ead51a05786a62918', 'versionType': 'git'}, {'status': 'affected', 'version': '6afc662e68b5f988282ff20afd58a89b1c279dca', 'lessThan': '2a9f9791653ba5ed3fb45bbffa8d63a7cd5cf706', 'versionType': 'git'}, {'status': 'affected', 'version': '6afc662e68b5f988282ff20afd58a89b1c279dca', 'lessThan': '4ce2d52f680c1d8bfdad7cce05b815ea7ca9790d', 'versionType': 'git'}, {'status': 'affected', 'version': '6afc662e68b5f988282ff20afd58a89b1c279dca', 'lessThan': '16bc237ce3c483b75575abea53cfb639745311ed', 'versionType': 'git'}, {'status': 'affected', 'version': '6afc662e68b5f988282ff20afd58a89b1c279dca', 'lessThan': '378acf3cf19b6af6cba55e8dd1154c4e1504bae8', 'versionType': 'git'}], 'programFiles': ['fs/f2fs/inode.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '4.15'}, {'status': 'unaffected', 'version': '0', 'lessThan': '4.15', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '5.10.261', 'versionType': 'semver', 'lessThanOrEqual': '5.10.*'}, {'status': 'unaffected', 'version': '5.15.212', 'versionType': 'semver', 'lessThanOrEqual': '5.15.*'}, {'status': 'unaffected', 'version': '6.1.178', 'versionType': 'semver', 'lessThanOrEqual': '6.1.*'}, {'status': 'unaffected', 'version': '6.6.145', 'versionType': 'semver', 'lessThanOrEqual': '6.6.*'}, {'status': 'unaffected', 'version': '6.12.96', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.39', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.3', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['fs/f2fs/inode.c'], 'defaultStatus': 'affected'}] -
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jul. 24, 2026
Action Type Old Value New Value Added Reference https://git.kernel.org/stable/c/3c8d6b4093aea40a20596f452289e7c22d84e6d5 Added Reference https://git.kernel.org/stable/c/76e1a05cf6d4051931d7fa4ead51a05786a62918 Added Reference https://git.kernel.org/stable/c/a08ee30dcbeff6b97df75c38c2589603ddde53a6 Added Reference https://git.kernel.org/stable/c/c3e05522daae4e7348a1ea81eeb321d25aa0fd3b Changed Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '6afc662e68b5f988282ff20afd58a89b1c279dca', 'lessThan': '2a9f9791653ba5ed3fb45bbffa8d63a7cd5cf706', 'versionType': 'git'}, {'status': 'affected', 'version': '6afc662e68b5f988282ff20afd58a89b1c279dca', 'lessThan': '4ce2d52f680c1d8bfdad7cce05b815ea7ca9790d', 'versionType': 'git'}, {'status': 'affected', 'version': '6afc662e68b5f988282ff20afd58a89b1c279dca', 'lessThan': '16bc237ce3c483b75575abea53cfb639745311ed', 'versionType': 'git'}, {'status': 'affected', 'version': '6afc662e68b5f988282ff20afd58a89b1c279dca', 'lessThan': '378acf3cf19b6af6cba55e8dd1154c4e1504bae8', 'versionType': 'git'}], 'programFiles': ['fs/f2fs/inode.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '4.15'}, {'status': 'unaffected', 'version': '0', 'lessThan': '4.15', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.12.96', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.39', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.3', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2-rc1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['fs/f2fs/inode.c'], 'defaultStatus': 'affected'}] [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '6afc662e68b5f988282ff20afd58a89b1c279dca', 'lessThan': '3c8d6b4093aea40a20596f452289e7c22d84e6d5', 'versionType': 'git'}, {'status': 'affected', 'version': '6afc662e68b5f988282ff20afd58a89b1c279dca', 'lessThan': 'a08ee30dcbeff6b97df75c38c2589603ddde53a6', 'versionType': 'git'}, {'status': 'affected', 'version': '6afc662e68b5f988282ff20afd58a89b1c279dca', 'lessThan': 'c3e05522daae4e7348a1ea81eeb321d25aa0fd3b', 'versionType': 'git'}, {'status': 'affected', 'version': '6afc662e68b5f988282ff20afd58a89b1c279dca', 'lessThan': '76e1a05cf6d4051931d7fa4ead51a05786a62918', 'versionType': 'git'}, {'status': 'affected', 'version': '6afc662e68b5f988282ff20afd58a89b1c279dca', 'lessThan': '2a9f9791653ba5ed3fb45bbffa8d63a7cd5cf706', 'versionType': 'git'}, {'status': 'affected', 'version': '6afc662e68b5f988282ff20afd58a89b1c279dca', 'lessThan': '4ce2d52f680c1d8bfdad7cce05b815ea7ca9790d', 'versionType': 'git'}, {'status': 'affected', 'version': '6afc662e68b5f988282ff20afd58a89b1c279dca', 'lessThan': '16bc237ce3c483b75575abea53cfb639745311ed', 'versionType': 'git'}, {'status': 'affected', 'version': '6afc662e68b5f988282ff20afd58a89b1c279dca', 'lessThan': '378acf3cf19b6af6cba55e8dd1154c4e1504bae8', 'versionType': 'git'}], 'programFiles': ['fs/f2fs/inode.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '4.15'}, {'status': 'unaffected', 'version': '0', 'lessThan': '4.15', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '5.10.261', 'versionType': 'semver', 'lessThanOrEqual': '5.10.*'}, {'status': 'unaffected', 'version': '5.15.212', 'versionType': 'semver', 'lessThanOrEqual': '5.15.*'}, {'status': 'unaffected', 'version': '6.1.178', 'versionType': 'semver', 'lessThanOrEqual': '6.1.*'}, {'status': 'unaffected', 'version': '6.6.145', 'versionType': 'semver', 'lessThanOrEqual': '6.6.*'}, {'status': 'unaffected', 'version': '6.12.96', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.39', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.3', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2-rc1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['fs/f2fs/inode.c'], 'defaultStatus': 'affected'}] -
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jul. 20, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H -
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jul. 19, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '6afc662e68b5f988282ff20afd58a89b1c279dca', 'lessThan': '2a9f9791653ba5ed3fb45bbffa8d63a7cd5cf706', 'versionType': 'git'}, {'status': 'affected', 'version': '6afc662e68b5f988282ff20afd58a89b1c279dca', 'lessThan': '4ce2d52f680c1d8bfdad7cce05b815ea7ca9790d', 'versionType': 'git'}, {'status': 'affected', 'version': '6afc662e68b5f988282ff20afd58a89b1c279dca', 'lessThan': '16bc237ce3c483b75575abea53cfb639745311ed', 'versionType': 'git'}, {'status': 'affected', 'version': '6afc662e68b5f988282ff20afd58a89b1c279dca', 'lessThan': '378acf3cf19b6af6cba55e8dd1154c4e1504bae8', 'versionType': 'git'}], 'programFiles': ['fs/f2fs/inode.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '4.15'}, {'status': 'unaffected', 'version': '0', 'lessThan': '4.15', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.12.96', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.39', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.3', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2-rc1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['fs/f2fs/inode.c'], 'defaultStatus': 'affected'}] Added Description In the Linux kernel, the following vulnerability has been resolved: f2fs: bound i_inline_xattr_size for non-inline-xattr inodes When the flexible_inline_xattr feature is enabled, do_read_inode() loads the on-disk i_inline_xattr_size unconditionally: if (f2fs_sb_has_flexible_inline_xattr(sbi)) fi->i_inline_xattr_size = le16_to_cpu(ri->i_inline_xattr_size); but sanity_check_inode() only range-checks it when the inode also has the FI_INLINE_XATTR flag set. An inode that carries an inline dentry or inline data but not FI_INLINE_XATTR -- the normal layout for an inline directory -- therefore keeps a fully attacker-controlled i_inline_xattr_size from a crafted image. get_inline_xattr_addrs() returns that value with no flag gating, so it feeds the inode geometry: MAX_INLINE_DATA() = 4 * (CUR_ADDRS_PER_INODE - i_inline_xattr_size - 1) NR_INLINE_DENTRY() = MAX_INLINE_DATA() * BITS_PER_BYTE / (...) addrs_per_page() = CUR_ADDRS_PER_INODE - i_inline_xattr_size A large i_inline_xattr_size drives MAX_INLINE_DATA() and NR_INLINE_DENTRY() negative, so make_dentry_ptr_inline() sets d->max (int) to a negative value. The inline directory walk then compares an unsigned long bit_pos against that negative d->max, which is promoted to a huge unsigned bound, and reads far past the inline area: while (bit_pos < d->max) /* fs/f2fs/dir.c */ ... test_bit_le(bit_pos, d->bitmap) / d->dentry[bit_pos] ... Mounting a crafted image and reading such a directory triggers an out-of-bounds read in f2fs_fill_dentries(); the same underflow also corrupts ADDRS_PER_INODE for regular files. Validate i_inline_xattr_size against MAX_INLINE_XATTR_SIZE whenever the flexible_inline_xattr feature is enabled -- i.e. whenever the value is loaded from disk and consumed -- and keep the lower MIN_INLINE_XATTR_SIZE bound gated on inodes that actually carry an inline xattr, so legitimate inodes with i_inline_xattr_size == 0 are still accepted. Added Reference https://git.kernel.org/stable/c/16bc237ce3c483b75575abea53cfb639745311ed Added Reference https://git.kernel.org/stable/c/2a9f9791653ba5ed3fb45bbffa8d63a7cd5cf706 Added Reference https://git.kernel.org/stable/c/378acf3cf19b6af6cba55e8dd1154c4e1504bae8 Added Reference https://git.kernel.org/stable/c/4ce2d52f680c1d8bfdad7cce05b815ea7ca9790d
EPSS is a daily estimate of the probability of exploitation activity
being observed over the next 30 days. Following chart shows the EPSS
score history of the vulnerability.