Vulnerability in linux (DEBIAN-CVE-2026-45851)

Summary

Vulnerability in linux (DEBIAN-CVE-2026-45851). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 6.12.85-1 or later.

Original description

The description as published by the source.

In the Linux kernel, the following vulnerability has been resolved: efi: Fix reservation of unaccepted memory table The reserve_unaccepted() function incorrectly calculates the size of the memblock reservation for the unaccepted memory table. It aligns the size of the table, but fails to account for cases where the table's starting physical address (efi.unaccepted) is not page-aligned. If the table starts at an offset within a page and its end crosses into a subsequent page that the aligned size does not cover, the end of the table will not be reserved. This can lead to the table being overwritten or inaccessible, causing a kernel panic in accept_memory(). This issue was observed when starting Intel TDX VMs with specific memory sizes (e.g., > 64GB). Fix this by calculating the end address first (including the unaligned start) and then aligning it up, ensuring the entire range is covered by the reservation.

Source: OSV.dev (Open Source Vulnerabilities) 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 DEBIAN-CVE-2026-45851 has been found in linux.
Risk of unauthorized operations or information disclosure.
What to do: upgrade linux to 6.12.85-1 or later.
If unsure, ask your IT team or search "linux DEBIAN-CVE-2026-45851" on the vendor's site.

DEBIAN-CVE-2026-45851 (linux)
Patched: 6.12.85-1 — 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 linux.

📍 Affected scope

Check the vendor advisory for the affected versions of linux.

🔥 Severity

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

🔧 How to fix

Update to 6.12.85-1.

🛡️ 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 'linux' . 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 'linux' . | 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 linux 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 linux to 6.12.85-1
```
ステージング環境で 6.12.85-1 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

Debian:13 linux

[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.12.85-1"}]}]

Debian:14 linux

[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.18.14-1"}]}]

References

advisory security-tracker.debian.org