CVE-2026-90263

CVE CVE-2026-90263EUVD EUVD-2026-81856Published 2026-09-17T16:08:00.000Z

What the advisory describes

In the Linux kernel, the following vulnerability has been resolved: btrfs: check if root is readonly when setting posix acl For a filesystem which has btrfs read-only property set to true, all write operations including acl and xattr should be denied. However, acl can still be set even if btrfs ro property is true. This happens because no function on the set_acl code path checks the root is readonly or not. It was checked in btrfs_setxattr_trans() but got removed in commit 353c2ea735e4 ("btrfs: remove redundant readonly root check in btrfs_setxattr_trans") That commit didn't check if all the callers properly check the root's read-only flag. A previous fix is commit b51111271b03 ("btrfs: check if root is readonly while setting security xattr"). Always check if the root is read-only before performing the set acl operation.

Source: EUVD (ENISA), in the words of the advisory.

Products the advisory names

These come from the advisory itself, not from any check we performed.

• Linux — Linux patch: 7.2.6; 353c2ea735e4b54fb6250861e67b51b1bcb47198 <01c2f41fc441f75b3f9326443372faceb1cb6638; patch: 0; 5.2; 353c2ea735e4b54fb6250861e67b51b1bcb47198 <d5602f96ff1e266f069b4d0d94f441050e057e06; patch: 7.3-rc1

The versions shown are the advisory's own. Patchlage compares no version numbers and derives no judgement from them — which version is installed is something a person has to look up.

Carried in the product catalogue

An estate covering these products can be recorded in Patchlage. An advisory about them appears in the next morning's situation report.

• Linux — Linux

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