How severe is CVE-2026-90044?

CVE-2026-90044 has a CVSS score of 7.8/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2026-90044?

CVE-2026-90044 affects the following packages: Kernel (Linux). Ecosystems affected: Linux.

How do I fix CVE-2026-90044?

Update Kernel to 6.18.51 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-90044 is resolved across your whole dependency graph.

How do I detect CVE-2026-90044 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-2026-90044 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-2026-90044?

O3 pinpoints whether CVE-2026-90044 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-2026-90044 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-90044 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-2026-90044 published, and has it been updated?

CVE-2026-90044 was published on September 16, 2026 and was last updated on September 17, 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

HIGH severity

CVE-2026-90044

HIGH

CVE-2026-90044 is a high-severity (CVSS 7.8) vulnerability in Kernel. O3 Security confirms whether CVE-2026-90044 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

usb: gadget: f_fs: Fix Use-After-Free in AIO error path

Published

Sep 16, 2026

Updated

Sep 17, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Sep 17, 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:

usb: gadget: f_fs: Fix Use-After-Free in AIO error path

In ffs_epfile_write_iter() and ffs_epfile_read_iter(), when ffs_epfile_io() fails with an error other than -EIOCBQUEUED, the io_data structure (p) is freed. However, for AIO operations, the kiocb cancel function was already armed and kiocb->private was set to p.

If a concurrent cancel operation (such as sys_io_cancel()) executes after ffs_epfile_io() fails but before the function frees p, a Use-After-Free can occur when the cancellation handler accesses the freed pointer.

To securely fix this race condition, we must properly un-arm the cancellation. Invoking kiocb->ki_complete() does exactly this by acquiring ctx->ctx_lock and safely removing the kiocb from the active sequence. In doing so, it ensures that a parallel io_cancel can no longer discover the kiocb, effectively closing the race window.

We then return -EIOCBQUEUED to notify the VFS layer that the kiocb has been consumed and it should avoid attempting to complete the request again or triggering subsequent completion handlers.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐧Linux	`Kernel`	≥ 4.0.0&&< 6.18.51	6.18.51

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 6.18.51 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-90044 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-2026-90044 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-2026-90044. 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: usb: gadget: f_fs: Fix Use-After-Free in AIO error path In ffs_epfile_write_iter() and ffs_epfile_read_iter(), when ffs_epfile_io() fails with an error other than -EIOCBQUEUED, the io_data structure (`p`) is freed. However, for AIO operations, the kiocb cancel function was already armed and kiocb->private was set to `p`. If a concurrent cancel operation (such as sys_io_cancel()) executes after ffs_epfile_io() fails but before the function frees `p`, a Use-After-Free can occur when the cancellation handler accesses the freed

O3 Security · Impact-Aware SCA

Is CVE-2026-90044 in your dependencies?

O3 detects CVE-2026-90044 across Linux dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

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