Linux kernel networking bug in IPv4 option parsing can crash or corrupt kernel memory across servers, routers and appliances running Linux; widespread OS-level impact.
CVE-2026-99064
Linux kernel IPv4 CIPSO parsing bug allows kernel memory corruption via crafted packets
Is CVE-2026-99064 being exploited?
Not confirmed. CVE-2026-99064 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 0.52% probability of exploitation in the next 30 days.
How severe is CVE-2026-99064?
CVE-2026-99064 is rated High with a CVSS score of 8.1. 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-2026-99064?
Yes. A fix has been recorded for CVE-2026-99064. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-99064 affect?
CVE-2026-99064 affects Linux kernel (IPv4 CIPSO option parsing), Servers, routers, and appliances running affected Linux kernels. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-99064?
Install updated kernel; block/strip IPv4 options at network edge until patched
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Remote memory corruption leading to kernel crashes or potential kernel-level code execution via crafted IPv4 options.
Patch when possible
- affected>= 89aa3619d141d6cfb6040a561aebb6d99d3e2285 and < b965977126a90e01825814c859ba4788691eddd3
- affected>= 89aa3619d141d6cfb6040a561aebb6d99d3e2285 and < 2200fe1d6148b78e1b8f00f4b2bd47760015077f
- affected>= 89aa3619d141d6cfb6040a561aebb6d99d3e2285 and < 6e49d611a9cfbaac927b8fa80ebd4f6b1f37ada0
- affected>= 89aa3619d141d6cfb6040a561aebb6d99d3e2285 and < 6d25ffca055a77787c21a36b66c253f76239411b
- affected6.10
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.