CVE-2025-40104

IPsec confidentiality and integrity loss via unnegotiated features

Published Oct 30, 2025 · Updated Oct 30, 2025

Mailbox feature confusion in Linux allows local users to expose IPsec keys and plaintext or accept unauthenticated traffic through ixgbevf. The driver selects IPsec and enhanced mailbox behavior from an API version without asking the physical-function driver which features it supports, then treats nonfailure replies as successful offload. Reachability requires control of an SR-IOV VF network namespace paired with an incompatible physical-function driver; the mismatch can also crash or wedge the VF.

CVSS severity7.8
High
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

Mailbox feature confusion in Linux allows local users to expose IPsec keys and plaintext or accept unauthenticated traffic through ixgbevf. The driver selects IPsec and enhanced mailbox behavior from an API version without asking the physical-function driver which features it supports, then treats nonfailure replies as successful offload. Reachability requires control of an SR-IOV VF network namespace paired with an incompatible physical-function driver; the mismatch can also crash or wedge the VF.

The record

CVE
CVE-2025-40104
Published
Oct 30, 2025
Updated
Oct 30, 2025
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 30, 2025CVE publishedPublication date reported by the CVE source.
  2. Oct 30, 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=0062e7cc955e0827a88570ed36ea511a7dcb391e <2e0aab9ddaf1428602c78f12064cd1e6ffcc4d18
  2. Affected versionversion=0062e7cc955e0827a88570ed36ea511a7dcb391e <871ac1cd4ce4804defcb428cbb003fd84c415ff4
  3. Affected versionversion=0062e7cc955e0827a88570ed36ea511a7dcb391e <a376e29b1b196dc90b50df7e5e3947e3026300c4
  4. Affected versionversion=0062e7cc955e0827a88570ed36ea511a7dcb391e <a7075f501bd33c93570af759b6f4302ef0175168
  5. Affected versionversion=0062e7cc955e0827a88570ed36ea511a7dcb391e <bf580112ed61736c2645a893413a04732505d4b1
  6. Affected versionversion=4.20

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=0062e7cc955e0827a88570ed36ea511a7dcb391e <2e0aab9ddaf1428602c78f12064cd1e6ffcc4d18; version=0062e7cc955e0827a88570ed36ea511a7dcb391e <871ac1cd4ce4804defcb428cbb003fd84c415ff4; version=0062e7cc955e0827a88570ed36ea511a7dcb391e <a376e29b1b196dc90b50df7e5e3947e3026300c4; version=0062e7cc955e0827a88570ed36ea511a7dcb391e <a7075f501bd33c93570af759b6f4302ef0175168; version=0062e7cc955e0827a88570ed36ea511a7dcb391e <bf580112ed61736c2645a893413a04732505d4b1; version=4.20

Published CVSS scores

7.8LinuxCVSS: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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

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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