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7.8
HIGH CVSS 3.1
CVE-2026-53389
net/tcp-ao: fix use-after-free of key in del_async path
Overview
Description

In the Linux kernel, the following vulnerability has been resolved: net/tcp-ao: fix use-after-free of key in del_async path In tcp_ao_delete_key(), the del_async path skips the current_key and rnext_key validity checks present in the synchronous path, assuming these pointers are always NULL on LISTEN sockets. However, if a key was added with set_current=1/set_rnext=1 while the socket was in CLOSE state, current_key and rnext_key will be non-NULL after listen() transitions the socket to LISTEN. When such a key is deleted with del_async=1, hlist_del_rcu() and call_rcu() free the key without clearing the dangling pointers. After the RCU grace period, getsockopt(TCP_AO_INFO) dereferences current_key->sndid and rnext_key->rcvid from freed slab memory. Clear current_key and rnext_key in the del_async path when they reference the key being deleted.

Details
INFO

Published Date :

July 19, 2026, 12:16 p.m.

Last Modified :

Aug. 17, 2026, 5:17 a.m.

Remotely Exploit :

No

Source :

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

The following products are affected by CVE-2026-53389 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
Clear key pointers in del_async path for TCP-AO to prevent use-after-free.
  • Clear current_key and rnext_key pointers.
  • Ensure validity checks in synchronous path.
  • Update the Linux kernel to the latest version.
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-2026-53389.

URL Resource
https://git.kernel.org/stable/c/5ba9950bc9078e19b69cca1e56d1553b125c6857 Patch
https://git.kernel.org/stable/c/6ce7ef41743740ce15c2061561b784148b565b3f Patch
https://git.kernel.org/stable/c/7ddc29a094d96e9b3aa280433c6dc443df9eabf2 Patch
https://git.kernel.org/stable/c/e77fbefd1269b5c123e7c651a1ebdce1b87d19a0 Patch
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-53389 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-2026-53389 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-2026-53389 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-2026-53389 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
    Changed Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': 'd6732b95b6fbbc6d5bb9d2f809e275763640c4a2', 'lessThan': '6ce7ef41743740ce15c2061561b784148b565b3f', 'versionType': 'git'}, {'status': 'affected', 'version': 'd6732b95b6fbbc6d5bb9d2f809e275763640c4a2', 'lessThan': 'e77fbefd1269b5c123e7c651a1ebdce1b87d19a0', 'versionType': 'git'}, {'status': 'affected', 'version': 'd6732b95b6fbbc6d5bb9d2f809e275763640c4a2', 'lessThan': '7ddc29a094d96e9b3aa280433c6dc443df9eabf2', 'versionType': 'git'}, {'status': 'affected', 'version': 'd6732b95b6fbbc6d5bb9d2f809e275763640c4a2', 'lessThan': '5ba9950bc9078e19b69cca1e56d1553b125c6857', 'versionType': 'git'}], 'programFiles': ['net/ipv4/tcp_ao.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '6.7'}, {'status': 'unaffected', 'version': '0', 'lessThan': '6.7', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.12.95', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.38', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.3', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2-rc1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['net/ipv4/tcp_ao.c'], 'defaultStatus': 'affected'}] [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': 'd6732b95b6fbbc6d5bb9d2f809e275763640c4a2', 'lessThan': '6ce7ef41743740ce15c2061561b784148b565b3f', 'versionType': 'git'}, {'status': 'affected', 'version': 'd6732b95b6fbbc6d5bb9d2f809e275763640c4a2', 'lessThan': 'e77fbefd1269b5c123e7c651a1ebdce1b87d19a0', 'versionType': 'git'}, {'status': 'affected', 'version': 'd6732b95b6fbbc6d5bb9d2f809e275763640c4a2', 'lessThan': '7ddc29a094d96e9b3aa280433c6dc443df9eabf2', 'versionType': 'git'}, {'status': 'affected', 'version': 'd6732b95b6fbbc6d5bb9d2f809e275763640c4a2', 'lessThan': '5ba9950bc9078e19b69cca1e56d1553b125c6857', 'versionType': 'git'}], 'programFiles': ['net/ipv4/tcp_ao.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '6.7'}, {'status': 'unaffected', 'version': '0', 'lessThan': '6.7', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.12.95', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.38', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.3', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['net/ipv4/tcp_ao.c'], 'defaultStatus': 'affected'}]
  • Initial Analysis by [email protected]

    Jul. 29, 2026

    Action Type Old Value New Value
    Added CWE CWE-416
    Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.7 up to (excluding) 6.12.95 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.13 up to (excluding) 6.18.38 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.19 up to (excluding) 7.1.3
    Added Reference Type kernel.org: https://git.kernel.org/stable/c/5ba9950bc9078e19b69cca1e56d1553b125c6857 Types: Patch
    Added Reference Type kernel.org: https://git.kernel.org/stable/c/6ce7ef41743740ce15c2061561b784148b565b3f Types: Patch
    Added Reference Type kernel.org: https://git.kernel.org/stable/c/7ddc29a094d96e9b3aa280433c6dc443df9eabf2 Types: Patch
    Added Reference Type kernel.org: https://git.kernel.org/stable/c/e77fbefd1269b5c123e7c651a1ebdce1b87d19a0 Types: Patch
  • CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    Jul. 20, 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
  • New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    Jul. 19, 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': 'd6732b95b6fbbc6d5bb9d2f809e275763640c4a2', 'lessThan': '6ce7ef41743740ce15c2061561b784148b565b3f', 'versionType': 'git'}, {'status': 'affected', 'version': 'd6732b95b6fbbc6d5bb9d2f809e275763640c4a2', 'lessThan': 'e77fbefd1269b5c123e7c651a1ebdce1b87d19a0', 'versionType': 'git'}, {'status': 'affected', 'version': 'd6732b95b6fbbc6d5bb9d2f809e275763640c4a2', 'lessThan': '7ddc29a094d96e9b3aa280433c6dc443df9eabf2', 'versionType': 'git'}, {'status': 'affected', 'version': 'd6732b95b6fbbc6d5bb9d2f809e275763640c4a2', 'lessThan': '5ba9950bc9078e19b69cca1e56d1553b125c6857', 'versionType': 'git'}], 'programFiles': ['net/ipv4/tcp_ao.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '6.7'}, {'status': 'unaffected', 'version': '0', 'lessThan': '6.7', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.12.95', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.38', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.3', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2-rc1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['net/ipv4/tcp_ao.c'], 'defaultStatus': 'affected'}]
    Added Description In the Linux kernel, the following vulnerability has been resolved: net/tcp-ao: fix use-after-free of key in del_async path In tcp_ao_delete_key(), the del_async path skips the current_key and rnext_key validity checks present in the synchronous path, assuming these pointers are always NULL on LISTEN sockets. However, if a key was added with set_current=1/set_rnext=1 while the socket was in CLOSE state, current_key and rnext_key will be non-NULL after listen() transitions the socket to LISTEN. When such a key is deleted with del_async=1, hlist_del_rcu() and call_rcu() free the key without clearing the dangling pointers. After the RCU grace period, getsockopt(TCP_AO_INFO) dereferences current_key->sndid and rnext_key->rcvid from freed slab memory. Clear current_key and rnext_key in the del_async path when they reference the key being deleted.
    Added Reference https://git.kernel.org/stable/c/5ba9950bc9078e19b69cca1e56d1553b125c6857
    Added Reference https://git.kernel.org/stable/c/6ce7ef41743740ce15c2061561b784148b565b3f
    Added Reference https://git.kernel.org/stable/c/7ddc29a094d96e9b3aa280433c6dc443df9eabf2
    Added Reference https://git.kernel.org/stable/c/e77fbefd1269b5c123e7c651a1ebdce1b87d19a0
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