Vulnerability in Kernel (CVE-2026-23034)

Summary

Vulnerability in Kernel (CVE-2026-23034). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 6.18.7 or later.

Original description

The description as published by the source.

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

drm/amdgpu/userq: Fix fence reference leak on queue teardown v2

The user mode queue keeps a pointer to the most recent fence in
userq->last_fence. This pointer holds an extra dma_fence reference.

When the queue is destroyed, we free the fence driver and its xarray,
but we forgot to drop the last_fence reference.

Because of the missing dma_fence_put(), the last fence object can stay
alive when the driver unloads. This leaves an allocated object in the
amdgpu_userq_fence slab cache and triggers

This is visible during driver unload as:

BUG amdgpu_userq_fence: Objects remaining on __kmem_cache_shutdown()
kmem_cache_destroy amdgpu_userq_fence: Slab cache still has objects
Call Trace:
kmem_cache_destroy
amdgpu_userq_fence_slab_fini
amdgpu_exit
__do_sys_delete_module

Fix this by putting userq->last_fence and clearing the pointer during
amdgpu_userq_fence_driver_free().

This makes sure the fence reference is released and the slab cache is
empty when the module exits.

v2: Update to only release userq->last_fence with dma_fence_put()
(Christian)

(cherry picked from commit 8e051e38a8d45caf6a866d4ff842105b577953bb)

Source: OSV.dev (Open Source Vulnerabilities) NVD OSV

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-2026-23034 has been found in Kernel.
Risk of unauthorized operations or information disclosure.
What to do: upgrade Kernel to 6.18.7 or later.
If unsure, ask your IT team or search "Kernel CVE-2026-23034" on the vendor's site.

CVE-2026-23034 (Kernel)
Patched: 6.18.7 — apply immediately
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

A vulnerability (unclassified) exists in Kernel.

📍 Affected scope

Check the vendor advisory for the affected versions of Kernel.

🔥 Severity

Severity: ?. Risk of unauthorized operations or information disclosure.

🔧 How to fix

Update to 6.18.7.

🛡️ 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. Run grep -r 'Kernel' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.

Response actions

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

1
Identify exposure identify
```
grep -r 'Kernel' . | grep -v node_modules
```
リポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で Kernel を grep し、稼働しているサービス・バージョンを把握する。
2
Apply patch patch
```
Upgrade Kernel to 6.18.7
```
ステージング環境で 6.18.7 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
3
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":"6.16.0"},{"fixed":"6.18.7"}]}]

Fix status by distribution

Fixed packages published by each distribution for this CVE

BellSoft Alpaquita BELL-CVE-2026-23034 linux-lts Fixed in: 6.18.35-r1
Debian DEBIAN-CVE-2026-23034 linux Fixed in: 6.18.8-1
Ubuntu UBUNTU-CVE-2026-23034 linux-hwe-edge