Widespread Linux kernel flaw allowing kernel memory corruption in a network-facing IPv6 code path; affects many distributions and could disrupt infrastructure.
CVE-2026-63984
Linux kernel IPv6 RPL hdrlen overflow causing kernel memory corruption.
Is CVE-2026-63984 being exploited?
Not confirmed. CVE-2026-63984 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 0.51% probability of exploitation in the next 30 days.
How severe is CVE-2026-63984?
CVE-2026-63984 is rated Critical. 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-2026-63984?
Yes. A fix has been recorded for CVE-2026-63984. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-63984 affect?
CVE-2026-63984 affects Linux kernel (ipv6_rpl_srh_decompress), Linux distributions using vulnerable kernels. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-63984?
Apply kernel/security updates or vendor backports; block RPL/IPv6 if unused.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Remote attackers can send crafted IPv6 RPL packets to corrupt kernel memory, causing DoS or potential remote code execution in the kernel network stack.
Immediate action required
- affected>= 8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3 and < 75b3680047bf09af8e7e471a7a6ddf2ce5847f56
- affected>= 8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3 and < fd238c51b0fa5390cceca9f1ac5a9ffda8063eed
- affected>= 8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3 and < 3618b34942b76471d044369bfd30d58c39068bf1
- affected>= 8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3 and < 97e06791368c01f0ad2a4b3269c2abe19485ca32
- affected>= 8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3 and < de02fc049352af5a9595f015511222d0a85c326b
- affected>= 8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3 and < 6fe1cb312038516cb4d9fa089d700af7059f1a64
- affected>= 8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3 and < c0487a9c1e116cf349e2d1f302d9019670460858
- affected>= 8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3 and < 9d5e7a46a9f6d8f503b41bfefef70659845f1679
- affected5.7
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.