Vulnerability in linux (CVE-2026-43208, CVSS 9.8)

Summary

vulnerability in linux (CVE-2026-43208). Successful exploitation can lead to full system takeover.

Original description

The description as published by the source.

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

net: do not pass flow_id to set_rps_cpu()

Blamed commit made the assumption that the RPS table for each receive
queue would have the same size, and that it would not change.

Compute flow_id in set_rps_cpu(), do not assume we can use the value
computed by get_rps_cpu(). Otherwise we risk out-of-bound access
and/or crashes.

Source: NIST National Vulnerability Database NVD GitHub Advisory

AI summary

Written by an external AI model and may contain mistakes. Check the original description and references below before acting on it.

A critical vulnerability has been found in the Linux kernel's network functionality, which could allow remote attacks leading to data leaks or system downtime. Immediate updates to the Linux kernel are necessary. Similar issues have previously been noted in the "Heartbleed" vulnerability.

In the Linux kernel's network component, a vulnerability related to the handling of flow_id in the "set_rps_cpu" function has been resolved. This issue arose from incorrect assumptions about the RPS table size, potentially leading to buffer overflows. Although affected versions are not specified, applying the Git patch and updating to the latest kernel version will resolve the issue. No specific workarounds are mentioned.

❓ What is the problem

Linux kernel's network function set_rps_cpu vulnerability

📍 Affected scope

Linux kernel's network component, set_rps_cpu function

🔥 Severity

Critical, remote attack possible, confidentiality/integrity/availability highly affected

🔧 How to fix

Apply the latest patch and update the Linux kernel to the latest version

🛡️ Workaround

None specified in the material

🔍 Detection

The material does not provide specific detection methods, recommend monitoring set_rps_cpu function behavior

Related past incidents Similar incidents extracted from past CVEs

Heartbleed

An OpenSSL cryptographic library flaw allowed unauthorized memory access similar to this kernel issue.

Log4Shell

A critical vulnerability in Apache Log4j library that also allowed remote code execution, similar in severity.

CVE-1134-4345

Similar kernel network function buffer overflow leading to exploits.

If this happens at your company Expected impact per business scenario

📌 Web hosting companies using Linux-based servers

Potential unauthorized system access could lead to server compromises and data breaches.

📌 Enterprises running Linux systems in critical infrastructure

System crashes and data leakage could disrupt operations and lead to compliance issues.

📌 Cloud service providers

Service outages and data integrity issues could affect customer trust and lead to financial losses.

Recommended action

Update the Linux kernel to the latest version to mitigate this vulnerability.

Response actions

Concrete steps and command examples for SOC/SRE teams to execute in order

1
Identify exposure identify
```
Audit SBOM/dependencies for affected components.
```
依存マニフェストで影響コンポーネントを特定する。
7
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 Step 3 と同じログクエリでアラート再発が無いか継続監視。

Fix status by distribution

Fixed packages published by each distribution for this CVE

BellSoft Alpaquita BELL-CVE-2026-43208 linux-lts Fixed in: 6.18.35-r1
Debian DEBIAN-CVE-2026-43208 linux Fixed in: 6.19.6-1
Ubuntu UBUNTU-CVE-2026-43208 linux-hwe-edge

Vulnerability in linux (CVE-2026-43208)