← Back
Summary
vulnerability in c (CVE-2026-43071). Confidential information can be exposed externally.
AI summary openai / gpt-4o
In the Linux kernel, a specific setting (`dhash_entries=1`) could lead to improper memory access, potentially allowing unauthorized access or disabling systems. Fixes involve limiting buckets to ensure security. This issue has occurred in the past, and applying the latest patches is crucial. System administrators should urgently apply these updates to secure their systems.
A vulnerability related to the `dentry_hashtable` in `dcache` can lead to out-of-bounds memory access if `dhash_entries=1` is configured, pointing to unallocated memory. The issue is resolved by setting a minimum of two buckets for `dhash_entries`. The affected version range is unspecified, and fixes involve updating the source. Detecting unpatched systems might be difficult; administrators should ensure configuration changes are applied to mitigate risks.
❓ What is the problem
A vulnerability in the Linux kernel's `dentry_hashtable` when `dhash_entries=1`, causing out-of-bounds memory access.
📍 Affected scope
Linux kernel, specifically in `dcache` related to `dentry_hashtable`.
🔥 Severity
Critical impact due to the potential for remote exploitation without required privileges or user interaction. CVSS 9.1.
🔧 How to fix
Adjust `dhash_entries` to ensure a minimum of two buckets in `dentry_hashtable`.
🛡️ Workaround
No specific workaround available; ensure the `dhash_entries` configuration is set correctly.
🔍 Detection
The vulnerability is configuration-sensitive; general detection is challenging without specific configuration checks.
Related past incidents Similar incidents extracted from past CVEs
A similar type of vulnerability exploiting memory access issues leading to data leaks.
If this happens at your company Expected impact per business scenario
📌 データセンターにあるLinuxサーバーが影響する場合
不正アクセスによるデータ漏洩やサービスダウンにつながる可能性が高い。
📌 Linux OSが基盤となっているECサイトで脆弱性の存在が公表された場合
顧客データが漏洩し、ブランドイメージに重大な影響を及ぼす。
📌 社内ITシステムでLinuxを広く利用している場合
システム停止や情報漏洩により業務運営に深刻な支障が生じる。
Recommended action
企業として、Linuxサーバーの設定を見直し、パッチを当てることを推奨。システムの継続的な監査と、セキュリティパッチ適用の迅速化が求められます。
Response Actions (7 steps)
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'c' . | 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 `c` を grep し、稼働しているサービス・バージョンを把握する。
-
7Post-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 Step 3 と同じログクエリでアラート再発が無いか継続監視。
References
- web https://git.kernel.org/stable/c/277cedabb0ab86baae83fa58218be13c6d3e5526
- web https://git.kernel.org/stable/c/426ef05e82ee52c8d0e95fc0808b7383d8352d73
- web https://git.kernel.org/stable/c/5718df131ab78897a9dd1f2e71c3ba732d4392af
- web https://git.kernel.org/stable/c/755b40903eff563768d4d96fd4ef51ec48adde3b
- web https://git.kernel.org/stable/c/ddd57ebce245f9c7e2f6902a6c087d6186d2385d
- web https://git.kernel.org/stable/c/f08fe8891c3eeb63b73f9f1f6d97aa629c821579
- web https://nvd.nist.gov/vuln/detail/CVE-2026-43071
- web https://github.com/advisories/GHSA-977x-crv2-w57m