Critical 9.8‑CVSS Linux TCP Use‑After‑Free (CVE‑2026‑98432) Patched by Red Hat; Ubuntu Fixes Still in Testing
What It Is — A use‑after‑free flaw in the IPv4 TCP implementation of the Linux kernel (CVE‑2026‑98432) allows a remote, unauthenticated attacker to execute arbitrary code with kernel privileges. The vulnerability scores 9.8 (CVSS v3.1) and is classified as a remote code execution (RCE) risk. Red Hat has released patched kernels for Enterprise Linux 8, 9 and 10. Ubuntu’s three current LTS releases have the fix only in an opt‑in testing channel, with no public rollout date announced. No public exploits have been observed yet, but the high severity and wide deployment of the affected kernels make rapid remediation essential.
Affected Products
- Red Hat Enterprise Linux 8, 9, 10 (patched)
- Ubuntu LTS 22.04, 24.04, 24.10 (fixes in testing)
Why It Matters for Trust & Control Assurance — This incident tests the “Vulnerability Management / Patch Management” control objective: organizations must demonstrate timely detection, assessment, and remediation of high‑severity flaws to satisfy multiple frameworks (e.g., NIST CSF 2.0, ISO 27001).
Recommended Actions
- Deploy Red Hat’s patched kernels immediately on all affected RHEL hosts.
- Verify kernel versions (
uname -r) and confirm the patch level via your configuration‑management inventory. - For Ubuntu systems, consider enrolling the testing channel or applying the patch manually; monitor Ubuntu advisories for the production rollout.
- Update your vulnerability‑management dashboard to record remediation dates and attach patch‑level evidence.
- Conduct a short‑term audit of any systems still running vulnerable kernels and prioritize remediation.