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major vulnerability· requires attention

Affects the widely used Linux kernel networking stack; remote packet-based memory corruption can impact servers, clouds, and network appliances across organizations.

Systems

CVE-2026-63922

CRITICAL
Critical
EPSS 0.71%Patch availableJul 21, 2026

IPv6 parsing bug in Linux kernel allows remote kernel memory corruption.

common questions

Is CVE-2026-63922 being exploited?

Not confirmed. CVE-2026-63922 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 0.71% probability of exploitation in the next 30 days.

How severe is CVE-2026-63922?

CVE-2026-63922 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-2026-63922?

Yes. A fix has been recorded for CVE-2026-63922. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.

What does CVE-2026-63922 affect?

CVE-2026-63922 affects Linux kernel (IPv6 exthdrs / ip6_parse_tlv), Linux distributions using affected kernels, Network-facing Linux appliances (routers, firewalls, cloud hosts). Confirm the exact affected versions against the vendor advisory before deciding you are exposed.

What should I do about CVE-2026-63922?

Apply kernel security update ASAP; if unable, block/inspect IPv6 at network edge.

Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.

executive summary
technical analysis
affected
Linux kernel (IPv6 exthdrs / ip6_parse_tlv)Linux distributions using affected kernelsNetwork-facing Linux appliances (routers, firewalls, cloud hosts)
impact

Remote crafted IPv6 packets can trigger kernel memory corruption, causing crashes or potential remote code execution in the kernel.

action required

Immediate action required

affected versions
Linux Linux
  • affected>= a831f5bbc89a9978795504be9e1ff412043f8f77 and < b3ac54e5c905f86d22b502eacb5686a282c5659f
  • affected>= a831f5bbc89a9978795504be9e1ff412043f8f77 and < f8aabed3ff3e986920cf02a2a2785e08e586b234
  • affected>= a831f5bbc89a9978795504be9e1ff412043f8f77 and < 1a11eb7431e3d2882f5bd5939c5a9bbc65ccf4d1
  • affected>= a831f5bbc89a9978795504be9e1ff412043f8f77 and < 12d957979e4a800167842f1b42be6a606d227ebe
  • affected>= a831f5bbc89a9978795504be9e1ff412043f8f77 and < ff375ed1cba81392346c5bfbf0bb7a13b2946f99
  • affected>= a831f5bbc89a9978795504be9e1ff412043f8f77 and < 751db1b802a067b7fff25880f4e9f9152a171538
  • affected>= a831f5bbc89a9978795504be9e1ff412043f8f77 and < 9b6dcc0a39fd71752937f0b6b3973e1416085dcf
  • affected>= a831f5bbc89a9978795504be9e1ff412043f8f77 and < f7b52afe3592eae66e160586b45a3f2242972c63
  • affected2.6.19
vendor says fixed in< 2.6.19, >= 5.10.259 and <= 5.10.*, >= 5.15.210 and <= 5.15.*, >= 6.1.176 and <= 6.1.*, >= 6.6.143 and <= 6.6.*, >= 6.12.93 and <= 6.12.*, >= 6.18.35 and <= 6.18.*, >= 7.0.12 and <= 7.0.*, >= 7.1 and <= *

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.

how to fix
Remediation steps are tailored for users whose stack is affected. Add this technology to your stack to see the fix checklist.
references
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