Categories
CVE-2026-64033 critical CVSS 9.8

Use-After-Free in Linux kernel (CVE-2026-64033)

Summary

Vulnerability in Linux kernel (CVE-2026-64033). Successful exploitation can lead to full system takeover.

Original description

The description as published by the source.

In the Linux kernel, the following vulnerability has been resolved:

RDMA/rtrs: Fix use-after-free in path file creation cleanup

In the error path of rtrs_srv_create_path_files(), the sysfs root folders
may already have been created and srv_path->kobj may already have been
initialized. If a later step fails, the cleanup currently calls
kobject_put(&srv_path->kobj) before
rtrs_srv_destroy_once_sysfs_root_folders(srv_path).

kobject_put() may drop the last reference to srv_path->kobj and invoke the
release callback, rtrs_srv_release(), which frees srv_path. The following
call to rtrs_srv_destroy_once_sysfs_root_folders(srv_path) then
dereferences srv_path internally to access srv_path->srv, resulting in a
use-after-free.

This failure path is reached before rtrs_srv_create_path_files() returns
success, so the successful-path lifetime handling is not involved.

Fix this by destroying the sysfs root folders before calling
kobject_put(&srv_path->kobj), so srv_path is still valid while the helper
accesses it.

This issue was found by a static analysis tool I am developing.

Source: NIST National Vulnerability Database NVD GitHub Advisory

Auto-generated summary

Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.

A vulnerability tracked as CVE-2026-64033 has been found in Linux kernel.
Successful exploitation can lead to full system takeover. CVSS score: 9.8/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Linux kernel CVE-2026-64033" on the vendor's site.

CVE-2026-64033 (Linux kernel) — CWE-416 / CVSS v3 9.8
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.

❓ What is the problem

Use-after-free (CWE-416) exists in Linux kernel.

📍 Affected scope

Check the vendor advisory for the affected versions of Linux kernel.

🔥 Severity

Severity: Critical (CVSS 9.8/10). Successful exploitation can lead to full system takeover.

🔧 How to fix

Update to the patched release per vendor advisory.

🛡️ Workaround

Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.

🔍 Detection

Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.

Response actions

Concrete steps and command examples for SOC/SRE teams to execute in order

  1. 1
    Identify exposure identify
    Audit SBOM/dependencies for affected components.

    資産台帳・SBOM・依存マニフェストで Linux kernel を使っているサービスとバージョンを洗い出す。

  2. 2
    Post-deployment verification verify
    Confirm patched version is live in production

    パッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。

Affected packages

Linux Kernel
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.15.209"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.175"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.17.0"},{"fixed":"6.6.142"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.12.92"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.18.34"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"7.0.11"}]}]

Fix status by distribution

Fixed packages published by each distribution for this CVE

References

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