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Fencer Vulns
high 8.4

CVE-2026-72197 json

fs/ntfs3: bound DeleteIndexEntryAllocation memmove length

published 2026-08-15 2 mo ago modified 2026-10-16 23 d ago also EUVD-2026-58955

cvss
8.4
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 8%
public exploits
0
none known

Summary

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

fs/ntfs3: bound DeleteIndexEntryAllocation memmove length

In do_action()'s DeleteIndexEntryAllocation case, e->size comes from an on-disk INDEX_BUFFER entry. When e->size makes e + e->size point past hdr + hdr->used, PtrOffset(e1, Add2Ptr(hdr, used)) returns a negative ptrdiff_t that is silently cast to a quasi-infinite size_t when passed to memmove(). The memmove then walks past the destination buffer.

The sibling DeleteIndexEntryRoot case at fslog.c:3540-3543 already carries the corresponding guard:

if (PtrOffset(e1, Add2Ptr(hdr, used)) < esize || Add2Ptr(e, esize) > Add2Ptr(lrh, rec_len) || used + esize > le32_to_cpu(hdr->total)) { goto dirty_vol; }

Apply the same shape to the allocation-path case. Also reject esize == 0: memmove(e, e, ...) is a no-op and leaves hdr->used unchanged, hiding a malformed entry from the existing check_index_header() walk.

Reproduced under UML+KASAN on mainline 8d90b09e6741 by mounting a crafted NTFS image: the unguarded memmove takes a length of 0xffffffffffffff00 and the kernel oopses in memmove+0x81/0x1a0 on the do_action+0x36a2 frame.

[almaz.alexandrovich@paragon-software.com: clang-formatted the changes]

Patch / fix

  • Linux Linux 5.15.212, 6.1.178, 6.6.145, 6.12.97, 6.18.40, 7.1.5, 7.2
  • linux Debian 12 6.1.180-1
  • linux Debian 13 6.12.100-1
  • linux Debian 14 7.1.5-1

debian advisories DEBIAN-CVE-2026-72197

  • linux Ubuntu 22.04 LTS 5.15.0-198.208
  • linux Ubuntu 24.04 LTS 6.8.0-147.147
  • linux Ubuntu 26.04 LTS 7.0.0-38.38
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1117.124
  • linux-aws Ubuntu 24.04 LTS 6.8.0-1067.70
  • linux-aws Ubuntu 26.04 LTS 7.0.0-1014.14
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1118.128
  • linux-gcp Ubuntu 24.04 LTS 6.8.0-1071.79

ubuntu advisories UBUNTU-CVE-2026-72197

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-72197 updated cvss 5.5

kernel: fs/ntfs3: bound DeleteIndexEntryAllocation memmove length

  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more Red Hat Enterprise Linux 10 kernel
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
23 d ago

Exploit prediction

0.18% chance of exploitation in the next 30 days, higher than 8% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 8.4 CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

  • Linux Linux

Classification

Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.