CVE-2026-89779
CVE-2026-89779 is a security vulnerability. O3 Security confirms whether CVE-2026-89779 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
In the Linux kernel, the following vulnerability has been resolved: fs/ntfs3: validate ef->size covers the record's name and value When an EA record has a non-zero ef->size, ntfs_read_ea()…
Description
In the Linux kernel, the following vulnerability has been resolved:
fs/ntfs3: validate ef->size covers the record's name and value
When an EA record has a non-zero ef->size, ntfs_read_ea() only checks that the record fits in the remaining buffer (ea_size > bytes), not that ef->size is large enough to hold the record's own name_len + 1 + elength.
A crafted image can pass validation with, e.g., ef->size = 24 but elength = 0xffff. ntfs_get_ea() then trusts elength and copies it out of the undersized record, reading past the kmalloc(info->size) allocation and leaking heap memory to userspace via getxattr():
BUG: KASAN: slab-out-of-bounds in ntfs_get_ea (fs/ntfs3/xattr.c:302) Read of size 65535 at addr ffff888100794550 by task exploit __asan_memcpy (mm/kasan/shadow.c:105) ntfs_get_ea (fs/ntfs3/xattr.c:302) ntfs_getxattr (fs/ntfs3/xattr.c:848) __vfs_getxattr (fs/xattr.c:441) vfs_getxattr (fs/xattr.c:474) do_getxattr (fs/xattr.c:800) path_getxattrat (fs/xattr.c:868) do_syscall_64 (arch/x86/entry/syscall_64.c:94)
The buggy address is located 80 bytes inside of allocated 84-byte region in cache kmalloc-96
Compute the size the record needs and require ef->size to cover it.
Detection & mitigation playbook
VulnerabilityDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for the affected component. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Remediation status
No patched version of the affected component has shipped for CVE-2026-89779 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-89779 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-89779. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-89779 in your dependencies?
O3 detects CVE-2026-89779 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.