CVE-2026-89779

CRITICALCVSS 9.1/10EPSS 0.21%

Last modified

CVE-2026-89779 is a critical-severity vulnerability rated 9.1/10 on the CVSS scale. 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.. EPSS estimates a 0.21% chance of exploitation in the next 30 days.

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.

Metrics

EPSS Probability
0.21%

10.8th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Source: CNA advisory (CVE.org). NVD analysis pending.

VendorProductVersions
LinuxLinux>= 333feb7ba84f69f9b423422417aaac54fd9e7c84, < b27e68ad818a4ca2cef8f35f97e75d756714c818; >= 000a9a72efa4a9df289bab9c9e8ba1639c72e0d6, < 28a924c7e67e6d71abeb04860b61166fecb027fc; >= 0e8235d28f3a0e9eda9f02ff67ee566d5f42b66b, < d585ed08308909c7e6fefb4e8a258aeb29b19ff9; >= 0e8235d28f3a0e9eda9f02ff67ee566d5f42b66b, < 077df8464cf24f8ffc82fb6efec2ae600686e699; >= 0e8235d28f3a0e9eda9f02ff67ee566d5f42b66b, < aab1880058ac767d3ea9388a9a7221c776c22c44; >= 0e8235d28f3a0e9eda9f02ff67ee566d5f42b66b, < c8a109c9e23a2c7fd548473dde728b2cb8188146; >= 0e8235d28f3a0e9eda9f02ff67ee566d5f42b66b, < c22f91d82cb9a29d22bdffdce6c803467984ad0c; >= 5.15.121, < 5.15.221; >= 6.1.40, < 6.1.188
LinuxLinux6.2

References

Timeline

Published
Last Modified
Status
Received

Frequently Asked Questions

What is CVE-2026-89779?
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.
How severe is CVE-2026-89779?
CVE-2026-89779 has a CVSS score of 9.1/10 (CRITICAL severity). The EPSS model estimates a 0.21% probability of exploitation in the next 30 days.
How do I fix CVE-2026-89779?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST