How severe is CVE-2026-90048?

CVE-2026-90048 has a CVSS score of 9.8/10, rated CRITICAL. Immediate patching is strongly recommended.

Which packages are affected by CVE-2026-90048?

CVE-2026-90048 affects the following packages: Kernel (Linux). Ecosystems affected: Linux.

How do I fix CVE-2026-90048?

Update Kernel to 6.6.157 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-90048 is resolved across your whole dependency graph.

How do I detect CVE-2026-90048 in my Linux dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Kernel. 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.

How do I mitigate CVE-2026-90048 if there is no patch (or I can't update yet)?

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 does O3 Security protect against CVE-2026-90048?

O3 pinpoints whether CVE-2026-90048 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is CVE-2026-90048 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-90048 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

When was CVE-2026-90048 published, and has it been updated?

CVE-2026-90048 was published on September 16, 2026 and was last updated on September 17, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐧

🐧 Linux

Not in CISA KEV

CRITICAL severity

CVE-2026-90048

CRITICAL

CVE-2026-90048 is a critical-severity (CVSS 9.8) remote code execution vulnerability in Kernel. O3 Security confirms whether CVE-2026-90048 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

fs/ntfs3: fix slab-out-of-bounds write in ni_create_attr_list()

Published

Sep 16, 2026

Updated

Sep 17, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Sep 17, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Real-World Exposure

1 pkg affected

🐧Kernel

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Linux packages — download data is not available via public APIs for these ecosystems.

Description

In the Linux kernel, the following vulnerability has been resolved:

fs/ntfs3: fix slab-out-of-bounds write in ni_create_attr_list()

ni_create_attr_list() allocates a fixed buffer of al_aligned(record_size) (== record_size) bytes and then walks every attribute of the primary MFT record, writing one ATTR_LIST_ENTRY per attribute and advancing the cursor by le_size(name_len), with no check against the end of the buffer; the total size is only computed after the loop.

A minimum-size resident attribute occupies SIZEOF_RESIDENT (0x18 = 24) bytes on disk, but an unnamed attribute expands to le_size(0) (0x20 = 32) bytes in the list. Because the number of attributes in a record is not bounded (mi_enum_attr() accepts arbitrarily many equal-type, nameless minimum-size attributes), a crafted record packed with such attributes produces a list larger than record_size and overflows the heap buffer.

This is reachable from a crafted, loop-mounted NTFS image: opening the file and adding an attribute (e.g. via setxattr) drives ntfs_set_ea() -> ni_insert_resident() -> ni_insert_attr() -> ni_ins_attr_ext() -> ni_create_attr_list().

BUG: KASAN: slab-out-of-bounds in ni_create_attr_list+0xc48/0x1058 Write of size 4 at addr ffff000008984c00 by task setfattr/345 ni_create_attr_list+0xc48/0x1058 ni_ins_attr_ext+0x510/0x7c0 ni_insert_attr+0x3f8/0x70c ni_insert_resident+0xc8/0x3b0 ntfs_set_ea+0x66c/0xd28 ntfs_setxattr+0x4d8/0x5b0 __arm64_sys_setxattr+0xa4/0x124 Allocated by task 345: ni_create_attr_list+0x188/0x1058 The buggy address belongs to the cache kmalloc-1k of size 1024 (the write lands at object+1024).

Size the buffer from the actual attributes instead of assuming a single record_size is always enough.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐧Linux	`Kernel`	≥ 5.15.0&&< 6.6.157	6.6.157

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Kernel. 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.
Fix
Update Kernel to 6.6.157 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-90048 is resolved across your whole dependency graph.
Workarounds
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-2026-90048 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-2026-90048. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

In the Linux kernel, the following vulnerability has been resolved: fs/ntfs3: fix slab-out-of-bounds write in ni_create_attr_list() ni_create_attr_list() allocates a fixed buffer of al_aligned(record_size) (== record_size) bytes and then walks every attribute of the primary MFT record, writing one ATTR_LIST_ENTRY per attribute and advancing the cursor by le_size(name_len), with no check against the end of the buffer; the total size is only computed after the loop. A minimum-size resident attribute occupies SIZEOF_RESIDENT (0x18 = 24) bytes on disk, but an unnamed attribute expands to le_siz

O3 Security · Impact-Aware SCA

Is CVE-2026-90048 in your dependencies?

O3 detects CVE-2026-90048 across Linux dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

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