Out-of-Bounds Read in Linux kernel (CVE-2025-39680)
Summary
Vulnerability in Linux kernel (CVE-2025-39680). 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:
i2c: rtl9300: Fix out-of-bounds bug in rtl9300_i2c_smbus_xfer
The data->block[0] variable comes from user. Without proper check,
the variable may be very large to cause an out-of-bounds bug.
Fix this bug by checking the value of data->block[0] first.
- commit 39244cc75482 ("i2c: ismt: Fix an out-of-bounds bug in
ismt_access()") - commit 92fbb6d1296f ("i2c: xgene-slimpro: Fix out-of-bounds bug in
xgene_slimpro_i2c_xfer()")
Source: NIST National Vulnerability Database NVD
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-2025-39680 has been found in Linux kernel.
Successful exploitation can lead to full system takeover. CVSS score: 7.8/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Linux kernel CVE-2025-39680" on the vendor's site.
CVE-2025-39680 (Linux kernel) — CWE-125 / CVSS v3 7.8
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.
Out-of-bounds read (CWE-125) exists in Linux kernel.
Check the vendor advisory for the affected versions of Linux kernel.
Severity: High (CVSS 7.8/10). Successful exploitation can lead to full system takeover.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
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
-
1Identify 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。
-
2Post-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
Fix status by distribution
Fixed packages published by each distribution for this CVE
- BellSoft Alpaquita BELL-CVE-2025-39680 linux-lts Fixed in: 6.18.35-r1
- Debian DEBIAN-CVE-2025-39680 linux Fixed in: 6.16.5-1
- Ubuntu UBUNTU-CVE-2025-39680 linux-hwe-edge
References
- advisory github.com
- advisory nvd.nist.gov
- package git.kernel.org
- web git.kernel.org
- web git.kernel.org