CVE-2026-80674 ntfs: validate resident attribute lists and harden the validator
A crafted resident attribute list in the Linux kernel NTFS driver causes out-of-bounds reads, potentially leading to denial of service or information disclosure.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-80674?
CVE-2026-80674 is a critical memory corruption vulnerability in Linux, published on 28 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
ntfs: validate resident attribute lists and harden the validator
A base inode's $ATTRIBUTE_LIST is sanity-checked by load_attribute_list() only on the non-resident path; ntfs_read_locked_inode() copies a *resident* attribute list into ni->attr_list with a plain memcpy() and no validation at all. Every subsequent walk of ni->attr_list -- ntfs_external_attr_find(), ntfs_inode_attach_all_extents() and ntfs_attrlist_need() -- then trusts the entries are well-formed and reads attr_list_entry fixed-header fields (lowest_vcn at offset 8, mft_reference at offset 16, and the name) with bounds that assume validation already happened. A crafted resident attribute list therefore reaches those walks unvalidated and can drive out-of-bounds reads of the attribute-list buffer.
load_attribute_list() itself reads ale->name_offset (offset 7), ale->mft_reference (offset 16) and the name length under only an "al < al_start + size" bound, so its own validation loop can over-read the fixed header of a truncated trailing entry by a few bytes.
Factor the per-entry validation into ntfs_attr_list_entry_is_valid(), which requires each entry's fixed header (offsetof(struct attr_list_entry, name)) to be in range before any field is dereferenced, that ale->length is a multiple of 8 covering the fixed header plus the name, and that the entry is in use and carries a live MFT reference. ntfs_attr_list_is_valid() walks the buffer with it and checks the entries tile it exactly. Use the list validator in load_attribute_list() (replacing the open-coded loop, closing its own over-read) and on the resident path in ntfs_read_locked_inode() (which previously skipped validation entirely); patches 2/3 reuse the per-entry helper at the other two attribute-list walks.
Which versions are affected by CVE-2026-80674?
How do I fix CVE-2026-80674?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-80674 being exploited?
There is no known exploitation of CVE-2026-80674 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-80674, GHSA-2h39-9r89-9rx3, UBUNTU-CVE-2026-80674.