CVE-2025-39917

Kernel memory corruption via undersized crypto dynptr

Published Oct 1, 2025 · Updated May 11, 2026

Out-of-bounds write in Linux kernel BPF crypto allows local users with root privileges to corrupt kernel memory using mismatched dynptrs. bpf_crypto_crypt passes src_len to the crypto backend without ensuring that the destination dynptr is at least that large, causing writes past pdst. The affected kfuncs are restricted to root, and no privilege gain beyond that access level has been demonstrated.

CVSS severity7.8
High
EPSS probability0.15%
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

Out-of-bounds write in Linux kernel BPF crypto allows local users with root privileges to corrupt kernel memory using mismatched dynptrs. bpf_crypto_crypt passes src_len to the crypto backend without ensuring that the destination dynptr is at least that large, causing writes past pdst. The affected kfuncs are restricted to root, and no privilege gain beyond that access level has been demonstrated.

The record

CVE
CVE-2025-39917
Published
Oct 1, 2025
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-787, T1499.004
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Oct 1, 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=3e1c6f35409f9e447bf37f64840f5b65576bfb78 <0126358df12d6f476f79251d9c398ac5c1b3062d
  2. Affected versionversion=3e1c6f35409f9e447bf37f64840f5b65576bfb78 <c4be24ef0510c146dca4671effb127e97631534b
  3. Affected versionversion=3e1c6f35409f9e447bf37f64840f5b65576bfb78 <f9bb6ffa7f5ad0f8ee0f53fc4a10655872ee4a14
  4. Affected versionversion=6.10

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

The Linux Kernel Organization · Linuxversion=3e1c6f35409f9e447bf37f64840f5b65576bfb78 <0126358df12d6f476f79251d9c398ac5c1b3062d; version=3e1c6f35409f9e447bf37f64840f5b65576bfb78 <c4be24ef0510c146dca4671effb127e97631534b; version=3e1c6f35409f9e447bf37f64840f5b65576bfb78 <f9bb6ffa7f5ad0f8ee0f53fc4a10655872ee4a14; version=6.10

Published CVSS scores

7.0Amazon LinuxCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
7.8Canonical UbuntuCVSS: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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write
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

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