CVE-2025-39715

Kernel crash via unchecked PA-RISC LWS access

Published Sep 5, 2025 · Updated Sep 5, 2025

Improper access validation in the PA-RISC gateway page in Linux allows local users to cause a kernel crash via crafted LWS calls. The gateway's privilege-level-0 load and stbys,e probes cannot raise a privilege-level-3 read interruption, so LWS compare-and-swap proceeds against a user-read-protected address. Reachability requires local low-privileged code on a PA-RISC system, and the published impact is a service interruption rather than 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

Improper access validation in the PA-RISC gateway page in Linux allows local users to cause a kernel crash via crafted LWS calls. The gateway's privilege-level-0 load and stbys,e probes cannot raise a privilege-level-3 read interruption, so LWS compare-and-swap proceeds against a user-read-protected address. Reachability requires local low-privileged code on a PA-RISC system, and the published impact is a service interruption rather than data disclosure or modification.

The record

CVE
CVE-2025-39715
Published
Sep 5, 2025
Updated
Sep 5, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499
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=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <8bccf47adbf658293528e86960e6d6f736b1c9f7
  2. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <9b6af875baba9c4679b55f4561e201485451305f
  3. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <bc0a24c24ceebabb5ba65900e332233d79e625e6
  4. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <e8b496c52aa0c6572d88db7cab85aeea6f9c194d
  5. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <f6334f4ae9a4e962ba74b026e1d965dfdf8cbef8

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <8bccf47adbf658293528e86960e6d6f736b1c9f7; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <9b6af875baba9c4679b55f4561e201485451305f; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <bc0a24c24ceebabb5ba65900e332233d79e625e6; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <e8b496c52aa0c6572d88db7cab85aeea6f9c194d; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <f6334f4ae9a4e962ba74b026e1d965dfdf8cbef8

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

T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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