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VulnerabilityPublished Updated

CVE-2026-43253: Linux kernel · iommu/amd: move wait_on_sem() out of spinlock

Affects Linux kernelSource CVE Database V5

0

Not known to be exploited · CVSS 7.5 High · fixed in f2f65b28d802a667119147444ec2ae33eebf9a58 : patch Linux kernel soon.

Data as of 26 Oct 2026, 14:18 UTC

CVSS 3.1 base score
7.5High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.3% chance of exploitation in 30 days – higher than 27% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CISA SSVC
Exploitation
No evidence of active exploitation and no public proof of concept
Automatable
Attackers can reliably automate steps 1–4 of the kill chain
Technical impact
Limited control over the software or limited information exposure

CISA SSVC assessment, 2026-10-16.

Patch
Available – fixed in f2f65b28d802a667119147444ec2ae33eebf9a58, e15768e68820142077bbca402d8e902f64ade1b0, d2a0cac10597068567d336e85fa3cbdbe8ca62bf +2
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 6 May 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

ProductAffectedFixed in
LinuxLinuxAffected
  • ≥ 4bf5beef578e46393f11eb69dda7d17a065e05ff, < f2f65b28d802a667119147444ec2ae33eebf9a58
Fixed in
  • f2f65b28d802a667119147444ec2ae33eebf9a58
LinuxLinuxAffected
  • ≥ 4bf5beef578e46393f11eb69dda7d17a065e05ff, < e15768e68820142077bbca402d8e902f64ade1b0
Fixed in
  • e15768e68820142077bbca402d8e902f64ade1b0
LinuxLinuxAffected
  • ≥ 4bf5beef578e46393f11eb69dda7d17a065e05ff, < d2a0cac10597068567d336e85fa3cbdbe8ca62bf
Fixed in
  • d2a0cac10597068567d336e85fa3cbdbe8ca62bf
LinuxLinuxAffected
  • ≥ 4bf5beef578e46393f11eb69dda7d17a065e05ff, < 496269d12072ecb219826485bdbec70c92a8eef5
Fixed in
  • 496269d12072ecb219826485bdbec70c92a8eef5
LinuxLinuxAffected
  • ≥ 4bf5beef578e46393f11eb69dda7d17a065e05ff, < 715c263119fd1b918a9fcbd8a36ea5b604a46324
Fixed in
  • 715c263119fd1b918a9fcbd8a36ea5b604a46324
LinuxLinuxAffected
  • =4.9
Fixed in–

Description

In the Linux kernel, the following vulnerability has been resolved: iommu/amd: move wait_on_sem() out of spinlock With iommu.strict=1, the existing completion wait path can cause soft lockups under stressed environment, as wait_on_sem() busy-waits under the spinlock with interrupts disabled. Move the completion wait in iommu_completion_wait() out of the spinlock. wait_on_sem() only polls the hardware-updated cmd_sem and does not require iommu->lock, so holding the lock during the busy wait unnecessarily increases contention and extends the time with interrupts disabled.

References

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