Vulnerability in Kernel (CVE-2026-23304)
Summary
Vulnerability in Kernel (CVE-2026-23304). Risk of unauthorized operations or information disclosure. 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:
ipv6: fix NULL pointer deref in ip6_rt_get_dev_rcu()
l3mdev_master_dev_rcu() can return NULL when the slave device is being
un-slaved from a VRF. All other callers deal with this, but we lost
the fallback to loopback in ip6_rt_pcpu_alloc() -> ip6_rt_get_dev_rcu()
with commit 4832c30d5458 ("net: ipv6: put host and anycast routes on
device with address").
KASAN: null-ptr-deref in range [0x0000000000000108-0x000000000000010f]
RIP: 0010:ip6_rt_pcpu_alloc (net/ipv6/route.c:1418)
Call Trace:
ip6_pol_route (net/ipv6/route.c:2318)
fib6_rule_lookup (net/ipv6/fib6_rules.c:115)
ip6_route_output_flags (net/ipv6/route.c:2607)
vrf_process_v6_outbound (drivers/net/vrf.c:437)
I was tempted to rework the un-slaving code to clear the flag first
and insert synchronize_rcu() before we remove the upper. But looks like
the explicit fallback to loopback_dev is an established pattern.
And I guess avoiding the synchronize_rcu() is nice, too.
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-2026-23304 has been found in Kernel.
Risk of unauthorized operations or information disclosure. CVSS score: 5.5/10.
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-2026-23304" on the vendor's site.
CVE-2026-23304 (Kernel) — CWE-476 / CVSS v3 5.5
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.
A vulnerability (CWE-476) exists in Kernel.
Check the vendor advisory for the affected versions of Kernel.
Severity: Medium (CVSS 5.5/10). Risk of unauthorized operations or information disclosure.
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-2026-23304 linux-lts Fixed in: 6.1.167-r0
- Debian DEBIAN-CVE-2026-23304 linux Fixed in: 5.10.257-1
- Ubuntu UBUNTU-CVE-2026-23304 linux-azure
References
- advisory nvd.nist.gov
- advisory github.com
- 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 git.kernel.org
- web github.com
- web cert-portal.siemens.com
- web cert-portal.siemens.com
- web cert-portal.siemens.com
- web cert-portal.siemens.com