CVE-2026-89616

What it is

In the Linux kernel, the following vulnerability has been resolved: fs/ntfs3: fix info-leak on partial LZNT decompress in ni_read_frame() ni_read_frame() decompresses an LZNT $DATA frame into the vmapped target pages and then trusts decompress_lznt()'s return value: unc_size = decompress_lznt(frame_ondisk, ondisk_size, frame_mem, frame_size); if ((ssize_t)unc_size < 0) err = unc_size; else if (!unc_size || unc_size > frame_size) err = -EINVAL; decompress_lznt() stops as soon as the compressed stream is exhausted (e.g. a zero chunk header) and returns the number of bytes it actually wrote, which may be far less than frame_size. The bytes between unc_size and frame_size are never written. The only memset() that follows zeroes the region beyond i_valid; when the frame lies entirely within the file's valid size that memset() does not run, so the gap retains whatever was in the just-vmapped pages. All pages are then marked uptodate and returned to userspace, disclosing uninitialized (recently-freed) kernel page memory. A crafted compressed file whose stream decompresses to only a few bytes leaks the remainder of every frame on a plain read(2), which is enough to recover kernel pointers and defeat KASLR. Zero the [unc_size, frame_size) tail immediately after a successful LZNT decompress so the remainder reads back as zero.

At a glance

Exploitability

Can be exploited over the network without logging in. High risk of data exposure.

Exploit odds

0.4% chance of exploitation in the next 30 days (EPSS).

Fix

No patch or advisory is linked yet. Look at mitigations or restrict exposure.

Timeline

1. 2026-09-11 20:19 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-10-19 09:17 UTC Last updatedMost recent change to the record

Details

Published

2026-09-11 20:19 UTC

Last modified

2026-10-19 09:17 UTC

Exploit probability

0.4% · EPSS, next 30 days

Record status

Received

Attack profile CVSS 3.1 · 7.5

Attack vector

Network

Complexity

Low

Privileges needed

None

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

None

Availability

None