Categories
CVE-2025-39738 high CVSS 7.3

Vulnerability in Linux Kernel (CVE-2025-39738)

Summary

Vulnerability in Linux Kernel (CVE-2025-39738). Data can be tampered with by attackers.

Original description

The description as published by the source.

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

btrfs: do not allow relocation of partially dropped subvolumes

[BUG]
There is an internal report that balance triggered transaction abort,
with the following call trace:

item 85 key (594509824 169 0) itemoff 12599 itemsize 33
extent refs 1 gen 197740 flags 2
ref#0: tree block backref root 7
item 86 key (594558976 169 0) itemoff 12566 itemsize 33
extent refs 1 gen 197522 flags 2
ref#0: tree block backref root 7
...
BTRFS error (device loop0): extent item not found for insert, bytenr 594526208 num_bytes 16384 parent 449921024 root_objectid 934 owner 1 offset 0
BTRFS error (device loop0): failed to run delayed ref for logical 594526208 num_bytes 16384 type 182 action 1 ref_mod 1: -117
------------[ cut here ]------------
BTRFS: Transaction aborted (error -117)
WARNING: CPU: 1 PID: 6963 at ../fs/btrfs/extent-tree.c:2168 btrfs_run_delayed_refs+0xfa/0x110 [btrfs]

And btrfs check doesn't report anything wrong related to the extent
tree.

[CAUSE]
The cause is a little complex, firstly the extent tree indeed doesn't
have the backref for 594526208.

The extent tree only have the following two backrefs around that bytenr
on-disk:

    item 65 key (594509824 METADATA_ITEM 0) itemoff 13880 itemsize 33
            refs 1 gen 197740 flags TREE_BLOCK
            tree block skinny level 0
            (176 0x7) tree block backref root CSUM_TREE
    item…

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-2025-39738 has been found in Linux Kernel.
Data can be tampered with by attackers. CVSS score: 7.3/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Linux Kernel CVE-2025-39738" on the vendor's site.

CVE-2025-39738 (Linux Kernel) — CVSS v3 7.3
Attack vector: local / 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 (unclassified) exists in Linux Kernel.

📍 Affected scope

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

🔥 Severity

Severity: High (CVSS 7.3/10). Data can be tampered with by attackers.

🔧 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。

Fix status by distribution

Fixed packages published by each distribution for this CVE

References

We use cookies for analytics and ad measurement. This setting applies to all Game co., Ltd. sites. Details