Affects the Linux kernel (widely deployed); allows BPF to modify page-cache/file data—enterprise-impacting risk requiring org-wide attention.
CVE-2026-63830
Linux kernel sk_msg BPF bug exposes writable page-cache pointers
Is CVE-2026-63830 being exploited?
Not confirmed. CVE-2026-63830 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 0.37% probability of exploitation in the next 30 days.
How severe is CVE-2026-63830?
CVE-2026-63830 is rated Critical with a CVSS score of 9.4. 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-2026-63830?
Yes. A fix has been recorded for CVE-2026-63830. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-63830 affect?
CVE-2026-63830 affects Linux kernel (net/sk_msg BPF paths), Servers and devices running affected kernel versions. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-63830?
Apply vendor kernel updates/backports now; restrict untrusted or unprivileged BPF.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
BPF programs can obtain writable ctx->data to modify page-cache/file contents, enabling data corruption, persistence, or local privilege escalation.
Immediate action required
- affected>= d3b18ad31f93d0b6bae105c679018a1ba7daa9ca and < f126eed589eec6f201405abbc398844042ef6d57
- affected>= d3b18ad31f93d0b6bae105c679018a1ba7daa9ca and < 31a110642b5fb5e61940cbcfb503445ac4f28017
- affected>= d3b18ad31f93d0b6bae105c679018a1ba7daa9ca and < 9bb86d8184b37503816150c4a6ad3c17dfdbe827
- affected>= d3b18ad31f93d0b6bae105c679018a1ba7daa9ca and < 0eb4c16c4adb262763bda870a8ed38a1a9dec7ec
- affected>= d3b18ad31f93d0b6bae105c679018a1ba7daa9ca and < d22cc92bc41290e5783a72375e0843d9435f6001
- affected>= d3b18ad31f93d0b6bae105c679018a1ba7daa9ca and < 1acdd14c0990dd1cd4b6534f00366d2e6dfce05f
- affected>= d3b18ad31f93d0b6bae105c679018a1ba7daa9ca and < 21ed9540a8e1906dfcbc1bb82ba9b4de4fa4bd6d
- affected>= d3b18ad31f93d0b6bae105c679018a1ba7daa9ca and < 406e8a651a7b854c41fecd5117bb282b3a6c2c6b
- affected4.20
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.