CVE-2026-49422
Local kernel use-after-free in TCP RACK via setsockopt enabling privilege escalation
Is CVE-2026-49422 being exploited?
Not confirmed. CVE-2026-49422 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.13% probability of exploitation in the next 30 days.
How severe is CVE-2026-49422?
CVE-2026-49422 is rated High with a CVSS score of 8.4. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-49422?
Yes. A fix has been recorded for CVE-2026-49422. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-49422 affect?
CVE-2026-49422 affects Linux kernel (RACK TCP implementation), Servers and endpoints running affected kernels. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-49422?
Apply vendor kernel updates when released; restrict local account access until patched.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Local unprivileged user can trigger a use-after-free in the kernel TCP RACK setsockopt path to gain root privileges or crash the system.
Patch when possible
- affected>= 15.1-RELEASE and < p1
- affected>= 15.0-RELEASE and < p11
- affected>= 14.4-RELEASE and < p7
- affected>= 14.3-RELEASE and < p16
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.