Out-of-Bounds Write in Kernel (CVE-2026-23359)
Summary
Out-of-bounds write in Kernel (CVE-2026-23359). Successful exploitation can lead to full system takeover. Mitigation: upgrade to 6.1.167, 6.6.130, 6.12.77, 6.18.17, 6.19.7 or later.
Original description
The description as published by the source.
In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix stack-out-of-bounds write in devmap
get_upper_ifindexes() iterates over all upper devices and writes their
indices into an array without checking bounds.
Also the callers assume that the max number of upper devices is
MAX_NEST_DEV and allocate excluded_devices[1+MAX_NEST_DEV] on the stack,
but that assumption is not correct and the number of upper devices could
be larger than MAX_NEST_DEV (e.g., many macvlans), causing a
stack-out-of-bounds write.
Add a max parameter to get_upper_ifindexes() to avoid the issue.
When there are too many upper devices, return -EOVERFLOW and abort the
redirect.
To reproduce, create more than MAX_NEST_DEV(8) macvlans on a device with
an XDP program attached using BPF_F_BROADCAST | BPF_F_EXCLUDE_INGRESS.
Then send a packet to the device to trigger the XDP redirect path.
Source: OSV.dev (Open Source Vulnerabilities) NVD GitHub Advisory OSV
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-2026-23359 has been found in Kernel.
Successful exploitation can lead to full system takeover. CVSS score: 7.8/10.
What to do: upgrade Kernel to 6.1.167, 6.6.130, 6.12.77, 6.18.17, 6.19.7 or later.
If unsure, ask your IT team or search "Kernel CVE-2026-23359" on the vendor's site.
CVE-2026-23359 (Kernel) — CWE-787 / CVSS v3 7.8
Attack vector: local / no user interaction
Patched: 6.1.167, 6.6.130, 6.12.77, 6.18.17, 6.19.7 — 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.
Out-of-bounds write (CWE-787) exists in Kernel.
Check the vendor advisory for the affected versions of Kernel.
Severity: High (CVSS 7.8/10). Successful exploitation can lead to full system takeover.
Update to 6.1.167, 6.6.130, 6.12.77, 6.18.17, 6.19.7.
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 6.1.167, 6.6.130, 6.12.77, 6.18.17, 6.19.7ステージング環境で 6.1.167, 6.6.130, 6.12.77, 6.18.17, 6.19.7 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-2026-23359 linux-lts Fixed in: 6.1.167-r0
- Debian DEBIAN-CVE-2026-23359 linux Fixed in: 6.1.170-1
- Ubuntu UBUNTU-CVE-2026-23359 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
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web cert-portal.siemens.com
- web cert-portal.siemens.com
- web github.com
- web cert-portal.siemens.com
- web cert-portal.siemens.com