Look up another CVE · open CVE-2026-89613 in the interactive tracker
CVE-2026-89613
ntfs: reject invalid empty mapping pairs
Published 2026-09-11 (37 days ago) by the Linux kernel CNA. Subsystem fs/ntfs. Debian urgency: unimportant.
What to do, per Debian release
Debian's own status for CVE-2026-89613 in every release this site tracks, and what each one means in practice. Every status below is the one the Debian Security Team publishes for this CVE. source
| Release | Status | Version | What this means |
|---|---|---|---|
| Debian 12bookworm | not affected | 6.1.190-1 | Nothing to do. bookworm never shipped the vulnerable code. |
| Debian 13trixie | not affected | 6.12.113-1 | Nothing to do. trixie never shipped the vulnerable code. |
| Debian 14forky | fixed | 7.2.6-1 | Update the kernel and reboot. Fixed in 7.2.6-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 7.2.6-1 | Update the kernel and reboot. Fixed in 7.2.6-1. A running kernel keeps the old code until the machine restarts. |
The vulnerability
What the bug is
Reject an attribute with empty mapping pairs if it has inconsistent highest VCN and size.
Where it lives
The fix touches these files. If the subsystem is one you do not use, the practical exposure is lower, though the package is still the vulnerable one.
fs/ntfs/runlist.c
- What this is
- NTFS FILESYSTEMMAINTAINERS section matched on fs/ntfs/ · linux-fsdevel@vger.kernel.org · Maintained
- Kernel module
- ntfs
Check it on the machine
grep -w CONFIG_NTFS_FS /boot/config-$(uname -r)Reads the booted kernel's own configuration, on the machine and nowhere else. =y is built in, =m is a module, and an is not set line means the code is not there.
lsmod | grep -w ntfsPrints a line if that module is loaded right now, and nothing if it is not. One that is not loaded can still be loaded later by anything that needs it.
Show whether Debian builds this, per release
Debian does not build this code in 1 release. It does build it in 2 releases, so the answer depends on which release the machine runs. The build rule could not be established for 1 release, so nothing is claimed about those.
- bookwormn
- trixie?
- forky, sidm
- n
- not enabled on any flavour - this release does not build the code
- ?
- not established - no Makefile entry for the affected file
- m
- a loadable module on every flavour - check lsmod, can be blacklisted
Where a release above reads "not established", no build rule for the affected file was found in that release's kernel tree. That is a gap in this lookup, not a finding that the code is absent.
- Build switch
- CONFIG_NTFS_FS
From the configuration Debian publishes for every kernel flavour it builds. It covers only the architectures Debian ships a linux-config package for, and nothing about a kernel you built yourself. Debian's own status above stays authoritative about the source package.MAINTAINERS kbuild Makefiles Debian linux-config packages
Signals
- Published
- 2026-09-11 (37 days ago)source
- CVSS
- 9.8 critical
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hsource recompute it - Attack vector
- network (AV:N)source
- EPSS
- 0.55%, higher than 45.0% of all CVEssource
- CISA KEV
- not listedthe KEV catalogue
- Debian urgency
- unimportantsource
- Subsystem
- fs/ntfs
Upstream fixes
The versions the CNA records as introducing and fixing this, and the commit for each. source
| Introduced | Fixed in | Commit |
|---|---|---|
| 7.1 | 7.2.4 | b0cc6dbc655e |
| 7.1 | 7.3 | 766062a82e1c |
Why the CNA scored it this way
Quoted from the kernel CNA's own scoring file, word for word. A highlighted metric carries the most severe value CVSS v3.1 defines for it, which is what pushes the score up. source
- AV:NAttack vector, network
- fs/ntfs registers ntfs_export_ops, so nfsd/ksmbd VFS reads on an exported NTFS volume reach ntfs_map_runlist()->ntfs_mapping_pairs_decompress() for crafted on-disk mapping pairs without local shell access.
- AC:LAttack complexity, low
- The attacker fully controls the empty mapping-pairs terminator, lowest/highest VCN, and allocated/data/initialized sizes; decompressing that attribute and merging the resulting degenerate runlist is deterministic with no race or victim-specific layout.
- PR:NPrivileges required, none
- Triggering the decoder needs only permission to cause server-side parsing of mounted NTFS metadata (guest/anonymous SMB or a permissive NFS export, or an unprivileged open/read on an already-mounted volume), not init-namespace root or CAP_SYS_ADMIN at trigger time.
- UI:NUser interaction, none
- After the crafted volume is mounted and exported, ordinary remote or local reads decompress the invalid empty mapping pairs and enter the merge path; no extra victim mount dialog, USB insertion, or confirmation is required during the attack.
- S:UScope, unchanged
- Heap corruption of the in-memory runlist and subsequent misdirected cluster I/O remain in the host kernel security domain and do not cross a VM, container, or IOMMU boundary to another authority.
- C:HConfidentiality impact, high
- Merging the degenerate unmapped runlist computes a negative source size and indexes src+ssize-1 / dst[marker] outside the allocation, an unbounded kernel heap out-of-bounds read that can disclose adjacent objects.
- I:HIntegrity impact, high
- The same merge performs out-of-bounds runlist writes via marker/loc arithmetic with ssize<0 and later I/O using corrupted VCN/LCN mappings, a kernel heap write primitive sufficient for control-flow hijacking.
- A:HAvailability impact, high
- WARN_ON on an entirely unmapped source runlist, heap out-of-bounds access, and corrupted runlist walks oops or panic the kernel, fully denying availability even when exploitation is not completed.