Vulnerability in Kernel (CVE-2026-31652)

Summary

Vulnerability in Kernel (CVE-2026-31652). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 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:

mm/damon/stat: deallocate damon_call() failure leaking damon_ctx

damon_stat_start() always allocates the module's damon_ctx object
(damon_stat_context). Meanwhile, if damon_call() in the function fails,
the damon_ctx object is not deallocated. Hence, if the damon_call() is
failed, and the user writes Y to “enabled” again, the previously
allocated damon_ctx object is leaked.

This cannot simply be fixed by deallocating the damon_ctx object when
damon_call() fails. That's because damon_call() failure doesn't guarantee
the kdamond main function, which accesses the damon_ctx object, is
completely finished. In other words, if damon_stat_start() deallocates
the damon_ctx object after damon_call() failure, the not-yet-terminated
kdamond could access the freed memory (use-after-free).

Fix the leak while avoiding the use-after-free by keeping returning
damon_stat_start() without deallocating the damon_ctx object after
damon_call() failure, but deallocating it when the function is invoked
again and the kdamond is completely terminated. If the kdamond is not yet
terminated, simply return -EAGAIN, as the kdamond will soon be terminated.

The issue was discovered [1] by sashiko.

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-2026-31652 has been found in Kernel.
Risk of unauthorized operations or information disclosure.
What to do: upgrade Kernel to 6.18.23, 6.19.13 or later.
If unsure, ask your IT team or search "Kernel CVE-2026-31652" on the vendor's site.

CVE-2026-31652 (Kernel)
Patched: 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 6.18.23, 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 6.18.23, 6.19.13
```
ステージング環境で 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":"6.17.0"},{"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-2026-31652 linux-lts Fixed in: 6.18.35-r1
Debian DEBIAN-CVE-2026-31652 linux Fixed in: 6.19.13-1
Ubuntu UBUNTU-CVE-2026-31652 linux-hwe-edge