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VulnerabilityPublished Updated

CVE-2026-45894: Linux kernel · Race Condition

Affects Linux kernelSource CVE Database V5

0

Not known to be exploited · CVSS 7.8 High · fixed in c36b0515c6445bd137ec8ad86ef5470c45d6e4bf : patch Linux kernel soon.

Data as of 26 Oct 2026, 13:47 UTC

CVSS 3.1 base score
7.8High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.1% chance of exploitation in 30 days – higher than 2% 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 cannot reliably automate steps 1–4 of the kill chain
Technical impact
Total control over the software or total information disclosure

CISA SSVC assessment, 2026-10-16.

Patch
Available – fixed in c36b0515c6445bd137ec8ad86ef5470c45d6e4bf, a84d30e8d2bacd21782a6481158b7c9c552f4868, 821807c167b7b48a41b95b6607c6b9f97600f7d9 +2
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 27 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
  • ≥ 0bbeb01a4fafbf8422e5c8882d461d6ac4f71e15, < c36b0515c6445bd137ec8ad86ef5470c45d6e4bf
Fixed in
  • c36b0515c6445bd137ec8ad86ef5470c45d6e4bf
LinuxLinuxAffected
  • ≥ 0bbeb01a4fafbf8422e5c8882d461d6ac4f71e15, < a84d30e8d2bacd21782a6481158b7c9c552f4868
Fixed in
  • a84d30e8d2bacd21782a6481158b7c9c552f4868
LinuxLinuxAffected
  • ≥ 0bbeb01a4fafbf8422e5c8882d461d6ac4f71e15, < 821807c167b7b48a41b95b6607c6b9f97600f7d9
Fixed in
  • 821807c167b7b48a41b95b6607c6b9f97600f7d9
LinuxLinuxAffected
  • ≥ 0bbeb01a4fafbf8422e5c8882d461d6ac4f71e15, < 949d71666e9dd19f21e7b4b53a88cd2c5b902858
Fixed in
  • 949d71666e9dd19f21e7b4b53a88cd2c5b902858
LinuxLinuxAffected
  • ≥ 0bbeb01a4fafbf8422e5c8882d461d6ac4f71e15, < 75ed00055c059dedc47b5daaaa2f8a7a019138ff
Fixed in
  • 75ed00055c059dedc47b5daaaa2f8a7a019138ff
LinuxLinuxAffected
  • =5.0
Fixed in–

Description

In the Linux kernel, the following vulnerability has been resolved: iommu/vt-d: Clear Present bit before tearing down PASID entry The Intel VT-d Scalable Mode PASID table entry consists of 512 bits (64 bytes). When tearing down an entry, the current implementation zeros the entire 64-byte structure immediately using multiple 64-bit writes. Since the IOMMU hardware may fetch these 64 bytes using multiple internal transactions (e.g., four 128-bit bursts), updating or zeroing the entire entry while it is active (P=1) risks a "torn" read. If a hardware fetch occurs simultaneously with the CPU zeroing the entry, the hardware could observe an inconsistent state, leading to unpredictable behavior or spurious faults. Follow the "Guidance to Software for Invalidations" in the VT-d spec (Section 6.5.3.3) by implementing the recommended ownership handshake: 1. Clear only the 'Present' (P) bit of the PASID entry. 2. Use a dma_wmb() to ensure the cleared bit is visible to hardware before proceeding. 3. Execute the required invalidation sequence (PASID cache, IOTLB, and Device-TLB flush) to ensure the hardware has released all cached references. 4. Only after the flushes are complete, zero out the remaining fields of the PASID entry. Also, add a dma_wmb() in pasid_set_present() to ensure that all other fields of the PASID entry are visible to the hardware before the Present bit is set.

References

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