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7.8
HIGH CVSS 3.1
CVE-2026-74270
handshake: Require admin permission for DONE command
Overview
Description

In the Linux kernel, the following vulnerability has been resolved: handshake: Require admin permission for DONE command ACCEPT and DONE are the two downcalls of the handshake genl family, both intended for use by the trusted handshake agent (tlshd). ACCEPT already requires GENL_ADMIN_PERM; DONE has no privilege check at all. The fd-lookup in handshake_nl_done_doit() only confirms that some pending handshake request exists for the supplied sockfd; it does not authenticate the sender. An unprivileged process that guesses or observes a valid sockfd can therefore submit a DONE with HANDSHAKE_A_DONE_STATUS == 0, leaving the kernel consumer to proceed as if the handshake succeeded. A non-zero status on a forged DONE tears down a legitimate in-flight handshake before tlshd can report its real result.

Details
INFO

Published Date :

Aug. 15, 2026, 6:22 a.m.

Last Modified :

Aug. 17, 2026, 6:19 a.m.

Remotely Exploit :

No

Source :

416baaa9-dc9f-4396-8d5f-8c081fb06d67
Impact
Affected Products

The following products are affected by CVE-2026-74270 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Linux linux_kernel
: Total Affected Vendor : 1 | Products : 1
Scoring
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 HIGH 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Solution
Apply kernel patches to enforce admin permissions for the handshake DONE command.
  • Patch the Linux kernel to add privilege checks.
  • Ensure tlshd has admin rights for handshake commands.
  • Recompile and deploy the updated kernel.
References
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-74270.

URL Resource
https://git.kernel.org/stable/c/25fb53e43ec006ac69b9e825a7e8a11d63a6083e
https://git.kernel.org/stable/c/4dafc411948469277b276724c3b2b4408c02c04c
https://git.kernel.org/stable/c/67cec2f1eb9e58719d622e92e2278ceda72dbd85
https://git.kernel.org/stable/c/81246a65303d9635266b1334490142caaf86a11f
https://git.kernel.org/stable/c/b6557f912509abe8e70223373dd7a44d1d4a0d6c
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-74270 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-74270 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-74270 vulnerability anywhere in the article.

Results are limited to the first 20 news articles due to potential performance issues.

The following table lists the changes that have been made to the CVE-2026-74270 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    Aug. 17, 2026

    Action Type Old Value New Value
    Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
    Changed Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '3b3009ea8abb713b022d94fba95ec270cf6e7eae', 'lessThan': '25fb53e43ec006ac69b9e825a7e8a11d63a6083e', 'versionType': 'git'}, {'status': 'affected', 'version': '3b3009ea8abb713b022d94fba95ec270cf6e7eae', 'lessThan': 'b6557f912509abe8e70223373dd7a44d1d4a0d6c', 'versionType': 'git'}, {'status': 'affected', 'version': '3b3009ea8abb713b022d94fba95ec270cf6e7eae', 'lessThan': '67cec2f1eb9e58719d622e92e2278ceda72dbd85', 'versionType': 'git'}, {'status': 'affected', 'version': '3b3009ea8abb713b022d94fba95ec270cf6e7eae', 'lessThan': '4dafc411948469277b276724c3b2b4408c02c04c', 'versionType': 'git'}, {'status': 'affected', 'version': '3b3009ea8abb713b022d94fba95ec270cf6e7eae', 'lessThan': '81246a65303d9635266b1334490142caaf86a11f', 'versionType': 'git'}], 'programFiles': ['Documentation/netlink/specs/handshake.yaml', 'net/handshake/genl.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '6.4'}, {'status': 'unaffected', 'version': '0', 'lessThan': '6.4', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.6.145', 'versionType': 'semver', 'lessThanOrEqual': '6.6.*'}, {'status': 'unaffected', 'version': '6.12.97', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.40', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.5', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2-rc1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['Documentation/netlink/specs/handshake.yaml', 'net/handshake/genl.c'], 'defaultStatus': 'affected'}] [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '3b3009ea8abb713b022d94fba95ec270cf6e7eae', 'lessThan': '25fb53e43ec006ac69b9e825a7e8a11d63a6083e', 'versionType': 'git'}, {'status': 'affected', 'version': '3b3009ea8abb713b022d94fba95ec270cf6e7eae', 'lessThan': 'b6557f912509abe8e70223373dd7a44d1d4a0d6c', 'versionType': 'git'}, {'status': 'affected', 'version': '3b3009ea8abb713b022d94fba95ec270cf6e7eae', 'lessThan': '67cec2f1eb9e58719d622e92e2278ceda72dbd85', 'versionType': 'git'}, {'status': 'affected', 'version': '3b3009ea8abb713b022d94fba95ec270cf6e7eae', 'lessThan': '4dafc411948469277b276724c3b2b4408c02c04c', 'versionType': 'git'}, {'status': 'affected', 'version': '3b3009ea8abb713b022d94fba95ec270cf6e7eae', 'lessThan': '81246a65303d9635266b1334490142caaf86a11f', 'versionType': 'git'}], 'programFiles': ['Documentation/netlink/specs/handshake.yaml', 'net/handshake/genl.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '6.4'}, {'status': 'unaffected', 'version': '0', 'lessThan': '6.4', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.6.145', 'versionType': 'semver', 'lessThanOrEqual': '6.6.*'}, {'status': 'unaffected', 'version': '6.12.97', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.40', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.5', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['Documentation/netlink/specs/handshake.yaml', 'net/handshake/genl.c'], 'defaultStatus': 'affected'}]
  • New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    Aug. 15, 2026

    Action Type Old Value New Value
    Added Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '3b3009ea8abb713b022d94fba95ec270cf6e7eae', 'lessThan': '25fb53e43ec006ac69b9e825a7e8a11d63a6083e', 'versionType': 'git'}, {'status': 'affected', 'version': '3b3009ea8abb713b022d94fba95ec270cf6e7eae', 'lessThan': 'b6557f912509abe8e70223373dd7a44d1d4a0d6c', 'versionType': 'git'}, {'status': 'affected', 'version': '3b3009ea8abb713b022d94fba95ec270cf6e7eae', 'lessThan': '67cec2f1eb9e58719d622e92e2278ceda72dbd85', 'versionType': 'git'}, {'status': 'affected', 'version': '3b3009ea8abb713b022d94fba95ec270cf6e7eae', 'lessThan': '4dafc411948469277b276724c3b2b4408c02c04c', 'versionType': 'git'}, {'status': 'affected', 'version': '3b3009ea8abb713b022d94fba95ec270cf6e7eae', 'lessThan': '81246a65303d9635266b1334490142caaf86a11f', 'versionType': 'git'}], 'programFiles': ['Documentation/netlink/specs/handshake.yaml', 'net/handshake/genl.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '6.4'}, {'status': 'unaffected', 'version': '0', 'lessThan': '6.4', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.6.145', 'versionType': 'semver', 'lessThanOrEqual': '6.6.*'}, {'status': 'unaffected', 'version': '6.12.97', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.40', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.5', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2-rc1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['Documentation/netlink/specs/handshake.yaml', 'net/handshake/genl.c'], 'defaultStatus': 'affected'}]
    Added Description In the Linux kernel, the following vulnerability has been resolved: handshake: Require admin permission for DONE command ACCEPT and DONE are the two downcalls of the handshake genl family, both intended for use by the trusted handshake agent (tlshd). ACCEPT already requires GENL_ADMIN_PERM; DONE has no privilege check at all. The fd-lookup in handshake_nl_done_doit() only confirms that some pending handshake request exists for the supplied sockfd; it does not authenticate the sender. An unprivileged process that guesses or observes a valid sockfd can therefore submit a DONE with HANDSHAKE_A_DONE_STATUS == 0, leaving the kernel consumer to proceed as if the handshake succeeded. A non-zero status on a forged DONE tears down a legitimate in-flight handshake before tlshd can report its real result.
    Added Reference https://git.kernel.org/stable/c/25fb53e43ec006ac69b9e825a7e8a11d63a6083e
    Added Reference https://git.kernel.org/stable/c/4dafc411948469277b276724c3b2b4408c02c04c
    Added Reference https://git.kernel.org/stable/c/67cec2f1eb9e58719d622e92e2278ceda72dbd85
    Added Reference https://git.kernel.org/stable/c/81246a65303d9635266b1334490142caaf86a11f
    Added Reference https://git.kernel.org/stable/c/b6557f912509abe8e70223373dd7a44d1d4a0d6c
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CVSS
Vulnerability Scoring Details
Base CVSS Score: 7.8
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality Impact
Integrity Impact
Availability Impact