CVE-2025-39803

Conditional kernel panic via stale UIC completion warning

Published Sep 15, 2025 · Updated May 11, 2026

Reachable assertion in the Linux kernel UFS core 6.13 through 6.16.3 allows local users to trigger a kernel warning. ufshcd_uic_cmd_compl() calls WARN_ON_ONCE(!cmd) after a delayed UIC completion interrupt is reenabled, although the command pointer has already been cleared. Reaching the path requires local low-privileged access and UFS activity; systems configured with panic_on_warn panic when the warning fires, while other systems emit a one-time warning.

CVSS severity7.8
High
EPSS probability0.14%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Reachable assertion in the Linux kernel UFS core 6.13 through 6.16.3 allows local users to trigger a kernel warning. ufshcd_uic_cmd_compl() calls WARN_ON_ONCE(!cmd) after a delayed UIC completion interrupt is reenabled, although the command pointer has already been cleared. Reaching the path requires local low-privileged access and UFS activity; systems configured with panic_on_warn panic when the warning fires, while other systems emit a one-time warning.

The record

CVE
CVE-2025-39803
Published
Sep 15, 2025
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-617, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 15, 2025CVE publishedPublication date reported by the CVE source.
  2. May 11, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=6.13
  2. Affected versionversion=fcd8b0450a9acbf3f0e88d749a72ef932df97663 <c0cc24c139e0f62859dbf88e050ba074cd93988f
  3. Affected versionversion=fcd8b0450a9acbf3f0e88d749a72ef932df97663 <e5203d89d59bfcbe1f348aa0d2dc4449a8ba644c

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=6.13; version=fcd8b0450a9acbf3f0e88d749a72ef932df97663 <c0cc24c139e0f62859dbf88e050ba074cd93988f; version=fcd8b0450a9acbf3f0e88d749a72ef932df97663 <e5203d89d59bfcbe1f348aa0d2dc4449a8ba644c

Published CVSS scores

7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-617Reachable Assertion
T1499.004Endpoint Denial of Service: Application 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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo