Out-of-Bounds Write in Kernel (CVE-2026-23378)
Summary
Out-of-bounds write in Kernel (CVE-2026-23378). 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:
net/sched: act_ife: Fix metalist update behavior
Whenever an ife action replace changes the metalist, instead of
replacing the old data on the metalist, the current ife code is appending
the new metadata. Aside from being innapropriate behavior, this may lead
to an unbounded addition of metadata to the metalist which might cause an
out of bounds error when running the encode op:
[ 138.423369][ C1] ==================================================================
[ 138.424317][ C1] BUG: KASAN: slab-out-of-bounds in ife_tlv_meta_encode (net/ife/ife.c:168)
[ 138.424906][ C1] Write of size 4 at addr ffff8880077f4ffe by task ife_out_out_bou/255
[ 138.425778][ C1] CPU: 1 UID: 0 PID: 255 Comm: ife_out_out_bou Not tainted 7.0.0-rc1-00169-gfbdfa8da05b6 #624 PREEMPT(full)
[ 138.425795][ C1] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[ 138.425800][ C1] Call Trace:
[ 138.425804][ C1]
[ 138.425808][ C1] dump_stack_lvl (lib/dump_stack.c:122)
[ 138.425828][ C1] print_report (mm/kasan/report.c:379 mm/kasan/report.c:482)
[ 138.425839][ C1] ? srso_alias_return_thunk (arch/x86/lib/retpoline.S:221)
[ 138.425844][ C1] ? _virt_addr_valid (./arch/x86/include/asm/preempt.h:95 (discriminator 1) ./include/linux/rcupdate.h:975 (discriminator 1) ./include/linux/mmzone.h:2207 (discriminator 1) arch/x86/mm/physaddr.c:54 (discriminator 1))
[ 138.425853][ C1] ? ife_tlv_meta…
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-2026-23378 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-2026-23378" on the vendor's site.
CVE-2026-23378 (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-2026-23378 linux-lts Fixed in: 6.1.167-r0
- Debian DEBIAN-CVE-2026-23378 linux
- Ubuntu UBUNTU-CVE-2026-23378 linux-azure
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 cert-portal.siemens.com
- web cert-portal.siemens.com
- web github.com
- web cert-portal.siemens.com
- web cert-portal.siemens.com