CVE-2026-74595
fscrypt: use the mount idmap for the owner check in fscrypt_ioctl_set_policy()
Description
In the Linux kernel, the following vulnerability has been resolved: fscrypt: use the mount idmap for the owner check in fscrypt_ioctl_set_policy() fscrypt_ioctl_set_policy() calls inode_owner_or_capable() with &nop_mnt_idmap before allowing an encryption policy to be set, instead of the idmap of the mount the ioctl was issued on. fscrypt is used by filesystems that support idmapped mounts (e.g. ext4, f2fs), so on such a mount this compares the caller's fsuid against the unmapped on-disk owner rather than the mapped owner: the actual owner can be wrongly denied with -EACCES and an unrelated caller wrongly allowed. Use file_mnt_idmap(filp) instead.
INFO
Published Date :
Aug. 22, 2026, 4:16 p.m.
Last Modified :
Aug. 22, 2026, 4:16 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Solution
- Update the Linux kernel to the latest stable version.
- Apply the fscrypt patch for idmap usage.
- Reboot the system after updating.
- Verify the authorization checks are now correct.
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-2026-74595.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-74595 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-2026-74595
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).
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The following list is the news that have been mention
CVE-2026-74595 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-74595 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.
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New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Aug. 22, 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': '14f3db5542e62bcf6fe088a09760ac52d55306c5', 'lessThan': '33b7e810ce09955aa02f3b632455cf5e7ac990a9', 'versionType': 'git'}, {'status': 'affected', 'version': '14f3db5542e62bcf6fe088a09760ac52d55306c5', 'lessThan': '6a67c460b12315033268dce597546984fe5739e7', 'versionType': 'git'}, {'status': 'affected', 'version': '14f3db5542e62bcf6fe088a09760ac52d55306c5', 'lessThan': '653e888a24c87b8bbeab44d7e558a1c1a3641088', 'versionType': 'git'}, {'status': 'affected', 'version': '14f3db5542e62bcf6fe088a09760ac52d55306c5', 'lessThan': '98516ba8b817f34e86bdd7a5b7a383cff75c3ddf', 'versionType': 'git'}, {'status': 'affected', 'version': '14f3db5542e62bcf6fe088a09760ac52d55306c5', 'lessThan': 'cf6c993c0feca7984797e634deba3c80342e199a', 'versionType': 'git'}], 'programFiles': ['fs/crypto/policy.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '5.12'}, {'status': 'unaffected', 'version': '0', 'lessThan': '5.12', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.6.152', 'versionType': 'semver', 'lessThanOrEqual': '6.6.*'}, {'status': 'unaffected', 'version': '6.12.104', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.45', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.9', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['fs/crypto/policy.c'], 'defaultStatus': 'affected'}] Added Description In the Linux kernel, the following vulnerability has been resolved: fscrypt: use the mount idmap for the owner check in fscrypt_ioctl_set_policy() fscrypt_ioctl_set_policy() calls inode_owner_or_capable() with &nop_mnt_idmap before allowing an encryption policy to be set, instead of the idmap of the mount the ioctl was issued on. fscrypt is used by filesystems that support idmapped mounts (e.g. ext4, f2fs), so on such a mount this compares the caller's fsuid against the unmapped on-disk owner rather than the mapped owner: the actual owner can be wrongly denied with -EACCES and an unrelated caller wrongly allowed. Use file_mnt_idmap(filp) instead. Added Reference https://git.kernel.org/stable/c/33b7e810ce09955aa02f3b632455cf5e7ac990a9 Added Reference https://git.kernel.org/stable/c/653e888a24c87b8bbeab44d7e558a1c1a3641088 Added Reference https://git.kernel.org/stable/c/6a67c460b12315033268dce597546984fe5739e7 Added Reference https://git.kernel.org/stable/c/98516ba8b817f34e86bdd7a5b7a383cff75c3ddf Added Reference https://git.kernel.org/stable/c/cf6c993c0feca7984797e634deba3c80342e199a