Vulnerability in Kernel (CVE-2026-23177)

Summary

Vulnerability in Kernel (CVE-2026-23177). Risk of unauthorized operations or information disclosure. Exploitable via index. Mitigation: upgrade to 6.12.70, 6.18.10 or later.

Original description

The description as published by the source.

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

mm, shmem: prevent infinite loop on truncate race

When truncating a large swap entry, shmem_free_swap() returns 0 when the
entry's index doesn't match the given index due to lookup alignment. The
failure fallback path checks if the entry crosses the end border and
aborts when it happens, so truncate won't erase an unexpected entry or
range. But one scenario was ignored.

When index points to the middle of a large swap entry, and the large
swap entry doesn't go across the end border, find_get_entries() will
return that large swap entry as the first item in the batch with
indices[0] equal to index. The entry's base index will be smaller
than indices[0], so shmem_free_swap() will fail and return 0 due to the
"base < index" check. The code will then call shmem_confirm_swap(), get
the order, check if it crosses the END boundary (which it doesn't), and
retry with the same index.

The next iteration will find the same entry again at the same index with
same indices, leading to an infinite loop.

Fix this by retrying with a round-down index, and abort if the index is
smaller than the truncate range.

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-2026-23177 has been found in Kernel.
Attackers can target a specific entry point like index over the network to misuse the product.
Risk of unauthorized operations or information disclosure.
What to do: upgrade Kernel to 6.12.70, 6.18.10 or later.
If unsure, ask your IT team or search "Kernel CVE-2026-23177" on the vendor's site.

CVE-2026-23177 (Kernel)
Attack surface: index
Patched: 6.12.70, 6.18.10 — 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. Attackers reach the vulnerable code path via index.

📍 Affected scope

Check the vendor advisory for the affected versions of Kernel. Attack surface: index.

🔥 Severity

Severity: ?. Risk of unauthorized operations or information disclosure.

🔧 How to fix

Update to 6.12.70, 6.18.10.

🛡️ 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 6.12.70, 6.18.10
```
ステージング環境で 6.12.70, 6.18.10 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":"6.12.0"},{"fixed":"6.12.70"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.10"}]}]

Fix status by distribution

Fixed packages published by each distribution for this CVE

BellSoft Alpaquita BELL-CVE-2026-23177 linux-lts Fixed in: 6.12.73-r0
Debian DEBIAN-CVE-2026-23177 linux Fixed in: 6.12.73-1
Ubuntu UBUNTU-CVE-2026-23177 linux-hwe-edge