# CVE-2026-89616

## Summary

- **CVE ID:** CVE-2026-89616
- **Severity:** HIGH
- **CVSS Score:** 7.5 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N)
- **CWE:** N/A
- **Published:** Sep 11, 2026
- **Last Modified:** Sep 14, 2026

## Description

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.

## Affected Products

- Linux — Linux (4342306f0f0d5ff4315a204d315c1b51b914fca5)
- Linux — Linux (5.15)
- Linux — Linux (0)
- Linux — Linux (6.12.109)
- Linux — Linux (6.18.50)
- Linux — Linux (7.2.4)
- Linux — Linux (7.3-rc1)
- Linux — Linux (5.15.221)
- Linux — Linux (6.1.188)
- Linux — Linux (6.6.157)

## References

- [CNA](https://git.kernel.org/stable/c/0f699ddb290a24b37e1bc9bf1e3c9dbccf564bea)
- [CNA](https://git.kernel.org/stable/c/376ee45659a4b943df672ad275c63da00655f929)
- [CNA](https://git.kernel.org/stable/c/4a1b39b2e10eb8de86265e80cf2be4396bc1dce4)
- [CNA](https://git.kernel.org/stable/c/35d1ea92c7d946e2ebdbe36cdb2c969c8704bebd)
- [CNA](https://git.kernel.org/stable/c/7d60a4c49af4d5cb88aa7cbf998d0408bd415055)
- [CNA](https://git.kernel.org/stable/c/cd40eee4923d104ebec9ac7513b971bc441e431d)
- [CNA](https://git.kernel.org/stable/c/77d8efd04745cda23858546afdbd9d07b591758e)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.41%
- **EPSS Percentile:** 35.2

---
_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-17._