Vulnerability in Kernel (CVE-2026-31647)

Summary

Vulnerability in Kernel (CVE-2026-31647). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 6.12.83, 6.18.23, 6.19.13 or later.

Original description

The description as published by the source.

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

idpf: fix PREEMPT_RT raw/bh spinlock nesting for async VC handling

Switch from using the completion's raw spinlock to a local lock in the
idpf_vc_xn struct. The conversion is safe because complete/_all() are
called outside the lock and there is no reason to share the completion
lock in the current logic. This avoids invalid wait context reported by
the kernel due to the async handler taking BH spinlock:

[ 805.726977] =============================
[ 805.726991] [ BUG: Invalid wait context ]
[ 805.727006] 7.0.0-rc2-net-devq-031026+ #28 Tainted: G S OE
[ 805.727026] -----------------------------
[ 805.727038] kworker/u261:0/572 is trying to lock:
[ 805.727051] ff190da6a8dbb6a0 (&vport_config->mac_filter_list_lock){+...}-{3:3}, at: idpf_mac_filter_async_handler+0xe9/0x260 [idpf]
[ 805.727099] other info that might help us debug this:
[ 805.727111] context-{5:5}
[ 805.727119] 3 locks held by kworker/u261:0/572:
[ 805.727132] #0: ff190da6db3e6148 ((wq_completion)idpf-0000:83:00.0-mbx){+.+.}-{0:0}, at: process_one_work+0x4b5/0x730
[ 805.727163] #1: ff3c6f0a6131fe50 ((work_completion)(&(&adapter->mbx_task)->work)){+.+.}-{0:0}, at: process_one_work+0x1e5/0x730
[ 805.727191] #2: ff190da765190020 (&x->wait#34){+.+.}-{2:2}, at: idpf_recv_mb_msg+0xc8/0x710 [idpf]
[ 805.727218] stack backtrace:
...
[ 805.727238] Workqueue: idpf-0000:83:00.0-mbx idpf_mbx_task [idpf]
[ 805.727247] Call Trace:
[…

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-2026-31647 has been found in Kernel.
Risk of unauthorized operations or information disclosure.
What to do: upgrade Kernel to 6.12.83, 6.18.23, 6.19.13 or later.
If unsure, ask your IT team or search "Kernel CVE-2026-31647" on the vendor's site.

CVE-2026-31647 (Kernel)
Patched: 6.12.83, 6.18.23, 6.19.13 — 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 6.12.83, 6.18.23, 6.19.13.

🛡️ 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 6.12.83, 6.18.23, 6.19.13
```
ステージング環境で 6.12.83, 6.18.23, 6.19.13 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":"6.9.0"},{"fixed":"6.12.83"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.23"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"6.19.13"}]}]

Fix status by distribution

Fixed packages published by each distribution for this CVE

BellSoft Alpaquita BELL-CVE-2026-31647 linux-lts Fixed in: 6.12.85-r0
Debian DEBIAN-CVE-2026-31647 linux Fixed in: 6.12.85-1
Ubuntu UBUNTU-CVE-2026-31647 linux-hwe-edge