Reference page — cumulative record through Monday, October 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.
CVE-2021-4135
n/a kernel — A memory leak vulnerability was found in the Linux kernel's eBPF for the Simulated networking device driver in the way user uses BPF for …
AV AC PR UI S C I A CVSS EPSS %ile KEV
L L L N U H N N 5.5 .0023 13.0 —
AFFECTED
Product Versions Fixed
kernel Linux kernel versions prior to 5.16-rc6 – —
TIMELINE
Dec 18 Reserved by redhat
Jul 14 Published (CNA: redhat)
Oct 8 ENRICHED — CVE-2021-4135 (kernel). Received CVSS 5.5 and CPE data from NVD.
Description
A memory leak vulnerability was found in the Linux kernel's eBPF for the Simulated networking device driver in the way user uses BPF for the device such that function nsim_map_alloc_elem being called. A local user could use this flaw to get unauthorized access to some data.
Lifecycle
Complete event history — 3 events, chronological
| Date | Event | Detail |
|---|
| December 18, 2021 | Reserved | Reserved by redhat |
| July 14, 2022 | Published | Published (CNA: redhat) |
| October 8, 2026 | ENRICHED | ENRICHED — CVE-2021-4135 (kernel). Received CVSS 5.5 and CPE data from NVD. |
Affected
Affected products and packages — 1 row
| Vendor | Product / Package | Ecosystem | Version introduced | Fixed |
|---|
| n/a | kernel | — | Linux kernel versions prior to 5.16-rc6 | — |
About this page
This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2021-4135 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Monday, October 19, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.
