CVE-2025-39699

Kernel crash via unchecked IOMMU lookup result

Published Sep 5, 2025 · Updated Sep 5, 2025

NULL pointer dereference in the RISC-V IOMMU driver in Linux 6.13 through 6.16.3 allows local users to crash the kernel. The riscv_iommu_iova_to_phys() function dereferences the result of riscv_iommu_pte_fetch() without handling a NULL return for an unmapped or never-mapped IOVA. Exploitation requires low-privileged local access and a system using the RISC-V IOMMU path; the resulting impact is a kernel crash without reported data disclosure or modification.

CVSS severity5.5
Medium
EPSS probability0.14%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

NULL pointer dereference in the RISC-V IOMMU driver in Linux 6.13 through 6.16.3 allows local users to crash the kernel. The riscv_iommu_iova_to_phys() function dereferences the result of riscv_iommu_pte_fetch() without handling a NULL return for an unmapped or never-mapped IOVA. Exploitation requires low-privileged local access and a system using the RISC-V IOMMU path; the resulting impact is a kernel crash without reported data disclosure or modification.

The record

CVE
CVE-2025-39699
Published
Sep 5, 2025
Updated
Sep 5, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-476, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 5, 2025CVE publishedPublication date reported by the CVE source.
  2. Sep 5, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=488ffbf181718b9ad8c1838cb249d60973e78eda <220c491490255b656672bb572b18460cd9155926
  2. Affected versionversion=488ffbf181718b9ad8c1838cb249d60973e78eda <99d4d1a070870aa08163af8ce0522992b7f35d8c
  3. Affected versionversion=6.13

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=488ffbf181718b9ad8c1838cb249d60973e78eda <220c491490255b656672bb572b18460cd9155926; version=488ffbf181718b9ad8c1838cb249d60973e78eda <99d4d1a070870aa08163af8ce0522992b7f35d8c; version=6.13

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-476NULL Pointer Dereference
T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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