Vulnerability in Kernel (CVE-2025-39903)
Summary
Vulnerability in Kernel (CVE-2025-39903). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 6.12.46, 6.16.6 or later.
Original description
The description as published by the source.
In the Linux kernel, the following vulnerability has been resolved:
of_numa: fix uninitialized memory nodes causing kernel panic
When there are memory-only nodes (nodes without CPUs), these nodes are not
properly initialized, causing kernel panic during boot.
of_numa_init
of_numa_parse_cpu_nodes
node_set(nid, numa_nodes_parsed);
of_numa_parse_memory_nodes
In of_numa_parse_cpu_nodes, numa_nodes_parsed gets updated only for nodes
containing CPUs. Memory-only nodes should have been updated in
of_numa_parse_memory_nodes, but they weren't.
Subsequently, when free_area_init() attempts to access NODE_DATA() for
these uninitialized memory nodes, the kernel panics due to NULL pointer
dereference.
This can be reproduced on ARM64 QEMU with 1 CPU and 2 memory nodes:
qemu-system-aarch64
-cpu host -nographic
-m 4G -smp 1
-machine virt,accel=kvm,gic-version=3,iommu=smmuv3
-object memory-backend-ram,size=2G,id=mem0
-object memory-backend-ram,size=2G,id=mem1
-numa node,nodeid=0,memdev=mem0
-numa node,nodeid=1,memdev=mem1
-kernel $IMAGE
-hda $DISK
-append "console=ttyAMA0 root=/dev/vda rw earlycon"
[ 0.000000] Booting Linux on physical CPU 0x0000000000 [0x481fd010]
[ 0.000000] Linux version 6.17.0-rc1-00001-gabb4b3daf18c-dirty (yintirui@local) (gcc (GCC) 12.3.1, GNU ld (GNU Binutils) 2.41) #52 SMP PREEMPT Mon Aug 18 09:49:40 CST 2025
[ 0.000000] KASLR enabled
[ 0.000000] random: crng init done
[ 0.000000] Machine model: linux,dummy-virt
[ 0.00…
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-2025-39903 has been found in Kernel.
Risk of unauthorized operations or information disclosure.
What to do: upgrade Kernel to 6.12.46, 6.16.6 or later.
If unsure, ask your IT team or search "Kernel CVE-2025-39903" on the vendor's site.
CVE-2025-39903 (Kernel)
Attack vector: local / no user interaction
Patched: 6.12.46, 6.16.6 — 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.
A vulnerability (unclassified) exists in Kernel.
Check the vendor advisory for the affected versions of Kernel.
Severity: ?. Risk of unauthorized operations or information disclosure.
Update to 6.12.46, 6.16.6.
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. Run grep -r 'Kernel' . 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
-
1Identify exposure identify
grep -r 'Kernel' . | 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
Kernelを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade Kernel to 6.12.46, 6.16.6ステージング環境で 6.12.46, 6.16.6 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。
-
3Post-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-2025-39903 linux-lts Fixed in: 6.12.51-r0
- Debian DEBIAN-CVE-2025-39903 linux Fixed in: 6.12.48-1
- Ubuntu UBUNTU-CVE-2025-39903 linux-hwe-edge
References
- advisory github.com
- advisory nvd.nist.gov
- package git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org