Vulnerability in Kernel (CVE-2026-23056)

Summary

Vulnerability in Kernel (CVE-2026-23056). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 5.10.249, 5.15.199, 6.1.162, 6.6.122, 6.12.68, 6.18.8 or later.

Original description

The description as published by the source.

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

uacce: implement mremap in uacce_vm_ops to return -EPERM

The current uacce_vm_ops does not support the mremap operation of
vm_operations_struct. Implement .mremap to return -EPERM to remind
users.

The reason we need to explicitly disable mremap is that when the
driver does not implement .mremap, it uses the default mremap
method. This could lead to a risk scenario:

An application might first mmap address p1, then mremap to p2,
followed by munmap(p1), and finally munmap(p2). Since the default
mremap copies the original vma's vm_private_data (i.e., q) to the
new vma, both munmap operations would trigger vma_close, causing
q->qfr to be freed twice(qfr will be set to null here, so repeated
release is ok).

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-2026-23056 has been found in Kernel.
Risk of unauthorized operations or information disclosure.
What to do: upgrade Kernel to 5.10.249, 5.15.199, 6.1.162, 6.6.122, 6.12.68, 6.18.8 or later.
If unsure, ask your IT team or search "Kernel CVE-2026-23056" on the vendor's site.

CVE-2026-23056 (Kernel)
Patched: 5.10.249, 5.15.199, 6.1.162, 6.6.122, 6.12.68, 6.18.8 — 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 5.10.249, 5.15.199, 6.1.162, 6.6.122, 6.12.68, 6.18.8.

🛡️ 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 5.10.249, 5.15.199, 6.1.162, 6.6.122, 6.12.68, 6.18.8
```
ステージング環境で 5.10.249, 5.15.199, 6.1.162, 6.6.122, 6.12.68, 6.18.8 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":"5.7.0"},{"fixed":"5.10.249"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.199"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.162"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.122"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.68"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.8"}]}]

Fix status by distribution

Fixed packages published by each distribution for this CVE

BellSoft Alpaquita BELL-CVE-2026-23056 linux-lts Fixed in: 6.1.163-r0
Debian DEBIAN-CVE-2026-23056 linux Fixed in: 5.10.249-1
Ubuntu UBUNTU-CVE-2026-23056 linux-hwe-edge