Categories
CVE-2025-39848 high CVSS 8.8

Vulnerability in Linux kernel (CVE-2025-39848)

Summary

Vulnerability in Linux kernel (CVE-2025-39848). 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:

ax25: properly unshare skbs in ax25_kiss_rcv()

Bernard Pidoux reported a regression apparently caused by commit
c353e8983e0d ("net: introduce per netns packet chains").

skb->dev becomes NULL and we crash in __netif_receive_skb_core().

Before above commit, different kind of bugs or corruptions could happen
without a major crash.

But the root cause is that ax25_kiss_rcv() can queue/mangle input skb
without checking if this skb is shared or not.

Many thanks to Bernard Pidoux for his help, diagnosis and tests.

We had a similar issue years ago fixed with commit 7aaed57c5c28
("phonet: properly unshare skbs in phonet_rcv()").

Source: NIST National Vulnerability Database NVD GitHub Advisory

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-2025-39848 has been found in Linux kernel.
Successful exploitation can lead to full system takeover. CVSS score: 8.8/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Linux kernel CVE-2025-39848" on the vendor's site.

CVE-2025-39848 (Linux kernel) — CWE-401 / CVSS v3 8.8
Attack vector: adjacent-network / unauthenticated / no user interaction
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 (CWE-401) exists in Linux kernel.

📍 Affected scope

Check the vendor advisory for the affected versions of Linux kernel.

🔥 Severity

Severity: High (CVSS 8.8/10). Successful exploitation can lead to full system takeover.

🔧 How to fix

Update to the patched release per vendor advisory.

🛡️ 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. Audit SBOM/dependencies to find affected services.

Response actions

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

  1. 1
    Identify exposure identify
    Audit SBOM/dependencies for affected components.

    資産台帳・SBOM・依存マニフェストで Linux kernel を使っているサービスとバージョンを洗い出す。

  2. 2
    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":"2.6.12"},{"fixed":"5.4.299"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.5.0"},{"fixed":"5.10.243"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.192"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.151"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.105"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.46"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.16.6"}]}]

Fix status by distribution

Fixed packages published by each distribution for this CVE

References

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