How severe is CVE-2026-72353?

No CVSS score has been assigned to CVE-2026-72353 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-72353?

CVE-2026-72353 affects the following packages: Kernel (Linux). Ecosystems affected: Linux.

How do I fix CVE-2026-72353?

Update Kernel to 7.1.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-72353 is resolved across your whole dependency graph.

How do I detect CVE-2026-72353 in my Linux dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Kernel. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

How do I mitigate CVE-2026-72353 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

How does O3 Security protect against CVE-2026-72353?

O3 pinpoints whether CVE-2026-72353 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is CVE-2026-72353 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-72353 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

When was CVE-2026-72353 published, and has it been updated?

CVE-2026-72353 was published on August 15, 2026 and was last updated on August 16, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐧 Linux

Not in CISA KEV

CVE-2026-72353

CVE-2026-72353 is a security vulnerability in Kernel. O3 Security confirms whether CVE-2026-72353 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

ntfs: avoid stale runlist element dereference in fallocate

Published

Aug 15, 2026

Updated

Aug 16, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Aug 16, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Real-World Exposure

1 pkg affected

🐧Kernel

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Linux packages — download data is not available via public APIs for these ecosystems.

Description

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

ntfs: avoid stale runlist element dereference in fallocate

ntfs_attr_fallocate() allocates holes and delayed allocations inside initialized size by looking up the current runlist element under ni->runlist.lock. The returned struct runlist_element is only a borrowed pointer into ni->runlist.rl. A writer can replace and free that array after the read lock is dropped, so later reads of rl->lcn, rl->length and rl->vcn can touch freed memory.

The buggy scenario involves two paths, with each column showing the order within that path:

ntfs_attr_fallocate():

Take ni->runlist.lock for read.
Get rl from ntfs_attr_find_vcn_nolock().
Drop ni->runlist.lock.
Read rl->lcn, rl->length and rl->vcn.

mmap page_mkwrite:

Enter ntfs_filemap_page_mkwrite().
Reach __ntfs_write_iomap_begin() and ntfs_attr_map_cluster().
Merge allocation state with ntfs_runlists_merge().
Reallocate ni->runlist.rl in ntfs_rl_realloc(), freeing the old array.

Validation reproduced this kernel report: BUG: KASAN: slab-use-after-free in ntfs_attr_fallocate+0xbb8/0xd00

Call Trace: <TASK> dump_stack_lvl+0x66/0xa0 print_report+0xce/0x630 ? ntfs_attr_fallocate+0xbb8/0xd00 ? srso_alias_return_thunk+0x5/0xfbef5 ? __virt_addr_valid+0x20d/0x410 ? ntfs_attr_fallocate+0xbb8/0xd00 kasan_report+0xe0/0x110 ? ntfs_attr_fallocate+0xbb8/0xd00 ntfs_attr_fallocate+0xbb8/0xd00 ? lock_acquire+0x2b8/0x2f0 ? __pfx_ntfs_attr_fallocate+0x10/0x10 ? 0xffffffffc0000095 ? down_write+0x10d/0x1e0 ntfs_fallocate+0x5c9/0x1d00 ? __pfx_ntfs_fallocate+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 ? lock_acquire+0x2b8/0x2f0 ? srso_alias_return_thunk+0x5/0xfbef5 ? selinux_file_permission+0x3a7/0x510 vfs_fallocate+0x29d/0xd30 __x64_sys_fallocate+0xc7/0x150 ? do_syscall_64+0x81/0x6a0 do_syscall_64+0x115/0x6a0 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Allocated by task 410: kasan_save_stack+0x33/0x60 kasan_save_track+0x14/0x30 __kasan_kmalloc+0xaa/0xb0 __kvmalloc_node_noprof+0x353/0x920 ntfs_rl_realloc+0x3f/0x110 ntfs_runlists_merge+0xaa3/0x3010 ntfs_attr_map_cluster+0x4e5/0xf80 ntfs_attr_fallocate+0x53f/0xd00 ntfs_fallocate+0x5c9/0x1d00 vfs_fallocate+0x29d/0xd30 __x64_sys_fallocate+0xc7/0x150 do_syscall_64+0x115/0x6a0 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 424: kasan_save_stack+0x33/0x60 kasan_save_track+0x14/0x30 kasan_save_free_info+0x3b/0x60 __kasan_slab_free+0x5f/0x80 kfree+0x307/0x580 ntfs_rl_realloc+0x6f/0x110 ntfs_runlists_merge+0x7b1/0x3010 ntfs_attr_map_cluster+0x4e5/0xf80 __ntfs_write_iomap_begin+0x8cd/0x2280 iomap_iter+0x6de/0x11e0 iomap_page_mkwrite+0x391/0x650 ntfs_filemap_page_mkwrite+0x1ac/0x400 do_page_mkwrite+0x15c/0x280 __handle_mm_fault+0xd6d/0x1ca0 handle_mm_fault+0x19c/0x470 do_user_addr_fault+0x23b/0x9c0 exc_page_fault+0x5c/0xc0 asm_exc_page_fault+0x26/0x30

Fix this by copying the needed runlist fields while the read lock is still held and using only those scalar snapshots after unlocking.

After the snapshot, ntfs_attr_map_cluster() can also find that the range is already mapped and return balloc=false. Only call ntfs_dio_zero_range() when new clusters were allocated, matching the write iomap path and preserving the zero-newly-allocated-holes behavior.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐧Linux	`Kernel`	≥ 7.1.0&&< 7.1.5	7.1.5

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for Kernel. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update Kernel to 7.1.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-72353 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-72353 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to CVE-2026-72353. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

In the Linux kernel, the following vulnerability has been resolved: ntfs: avoid stale runlist element dereference in fallocate ntfs_attr_fallocate() allocates holes and delayed allocations inside initialized size by looking up the current runlist element under ni->runlist.lock. The returned struct runlist_element is only a borrowed pointer into ni->runlist.rl. A writer can replace and free that array after the read lock is dropped, so later reads of rl->lcn, rl->length and rl->vcn can touch freed memory. The buggy scenario involves two paths, with each column showing the order within that p

O3 Security · Impact-Aware SCA

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