Vulnerability in Kernel (CVE-2025-37818)

Summary

Vulnerability in Kernel (CVE-2025-37818). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 6.1.136, 6.6.89, 6.12.26, 6.14.5 or later.

Original description

The description as published by the source.

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

LoongArch: Return NULL from huge_pte_offset() for invalid PMD

LoongArch's huge_pte_offset() currently returns a pointer to a PMD slot
even if the underlying entry points to invalid_pte_table (indicating no
mapping). Callers like smaps_hugetlb_range() fetch this invalid entry
value (the address of invalid_pte_table) via this pointer.

The generic is_swap_pte() check then incorrectly identifies this address
as a swap entry on LoongArch, because it satisfies the "!pte_present()
&& !pte_none()" conditions. This misinterpretation, combined with a
coincidental match by is_migration_entry() on the address bits, leads to
kernel crashes in pfn_swap_entry_to_page().

Fix this at the architecture level by modifying huge_pte_offset() to
check the PMD entry's content using pmd_none() before returning. If the
entry is invalid (i.e., it points to invalid_pte_table), return NULL
instead of the pointer to the slot.

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-2025-37818 has been found in Kernel.
Risk of unauthorized operations or information disclosure.
What to do: upgrade Kernel to 6.1.136, 6.6.89, 6.12.26, 6.14.5 or later.
If unsure, ask your IT team or search "Kernel CVE-2025-37818" on the vendor's site.

CVE-2025-37818 (Kernel)
Patched: 6.1.136, 6.6.89, 6.12.26, 6.14.5 — 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 6.1.136, 6.6.89, 6.12.26, 6.14.5.

🛡️ 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 6.1.136, 6.6.89, 6.12.26, 6.14.5
```
ステージング環境で 6.1.136, 6.6.89, 6.12.26, 6.14.5 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":"5.19.0"},{"fixed":"6.1.136"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.89"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.26"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.14.5"}]}]

Fix status by distribution

Fixed packages published by each distribution for this CVE

BellSoft Alpaquita BELL-CVE-2025-37818 linux-lts Fixed in: 6.1.140-r0
Debian DEBIAN-CVE-2025-37818 linux Fixed in: 6.1.137-1