iommu/iommufd: Fix IOPF group ownership UAF
CVE-2026-74520 · published 15 Aug 2026
How serious is it
- Severity: high, CVSS score 8.8 out of 10.
- No exploit prediction (EPSS) score yet.
- Not on the CISA list of exploited vulnerabilities.
- No public exploit in Exploit-DB.
Is your app affected by CVE-2026-74520?
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Who is affected
- Linux Linux: 34765cbc679c59ea5d952d738d2d16bf4aadc497 to < 8563099bc4b03e1894a983a394225d69b05d9277, 34765cbc679c59ea5d952d738d2d16bf4aadc497 to < 6da8f37419dd4c456f26fc203f04e000186f4b3d, 34765cbc679c59ea5d952d738d2d16bf4aadc497 to < 4e74a369236424114b94cf6a9f5ff9e848b430b4, 34765cbc679c59ea5d952d738d2d16bf4aadc497 to < 738e6f32e61d80b554e37015ecb7bc620b88001c
- Linux Linux: 6.11
How to check
- Find out whether you run the affected product and which version, then compare it with the versions above.
How to fix
Copies a prompt for Claude Code, Cursor or Codex that asks it to check whether you run this product.
- Apply the vendor's update or mitigation from the references below. If there is none yet, limit exposure of the affected service until there is.
- If a vulnerable version was live, check your logs and rotate the secrets that server could read.
The advisory
In the Linux kernel, the following vulnerability has been resolved:
iommu/iommufd: Fix IOPF group ownership UAF
iopf_group_alloc() links each last-page IOPF group into the generic IOPF
pending list before invoking the domain fault handler.
iommufd_fault_iopf_handler() also queued an accepted group in the
IOMMUFD deliver list without removing it from the generic pending list.
When detach or HWPT replacement drops the device's IOPF reference count
to zero, an IOMMU driver may call iopf_queue_remove_device(). That
function responds to and frees groups through the generic pending list
without removing the same groups from IOMMUFD's deliver list or response
xarray. A later read, response, or cleanup can then access the freed
group and cause a UAF.
Fix this by dequeuing an accepted group from the generic pending list
before IOMMUFD queues it for userspace response.
Make iopf_group_response() send a response regardless of pending-list
membership, so the dequeued group can still be completed by IOMMUFD.
Check your whole app
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References
- git.kernel.org/stable/c/8563099bc4b03e1894a983a394225d69b05d9277
- git.kernel.org/stable/c/6da8f37419dd4c456f26fc203f04e000186f4b3d
- git.kernel.org/stable/c/4e74a369236424114b94cf6a9f5ff9e848b430b4
- git.kernel.org/stable/c/738e6f32e61d80b554e37015ecb7bc620b88001c
Merged from CVE List. Last updated 25 Oct 2026. All vulnerabilities · RSS · JSON