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-2021-33624

CVE-2021-33624MEDIUM

n/a n/a — In kernel/bpf/verifier.c in the Linux kernel before 5.12.13, a branch can be mispredicted (e.g., because of type confusion) and consequen…

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   L   H   L   N  U  H  N  N    4.7   .0092   59.7     —

AFFECTED
  Product  Versions  Fixed
  n/a      n/a –     —

TIMELINE
  May 28  Reserved by mitre
  Jun 23  Published (CNA: mitre)
  Oct 8   ENRICHED — CVE-2021-33624. Received CVSS 4.7 and CPE data from NVD.
  Oct 8   EXPLOIT PUBLISHED — CVE-2021-33624. Public exploit reference added.

CWE-843 · CNA: mitre · CVSS v3.1 · 5 references · NVD status: Modified

Description

In kernel/bpf/verifier.c in the Linux kernel before 5.12.13, a branch can be mispredicted (e.g., because of type confusion) and consequently an unprivileged BPF program can read arbitrary memory locations via a side-channel attack, aka CID-9183671af6db.

Lifecycle

Complete event history — 4 events, chronological
Date	Event	Detail
May 28, 2021	Reserved	Reserved by mitre
June 23, 2021	Published	Published (CNA: mitre)
October 8, 2026	ENRICHED	ENRICHED — CVE-2021-33624. Received CVSS 4.7 and CPE data from NVD.
October 8, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2021-33624. Public exploit reference added.

Affected

Affected products and packages — 1 row
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
n/a	n/a	—	n/a	—

Weaknesses

CWE-843

References (5)

http://www.openwall.com/lists/oss-security/2021/06/21/1 [Exploit, Mailing List, Third Party Advisory]
https://github.com/benschlueter/CVE-2021-33624
https://github.com/torvalds/linux/commit/9183671af6dbf60a1219371d4ed73e23f43b49db [Patch, Third Party Advisory]
https://lists.debian.org/debian-lts-announce/2021/10/msg00010.html [Issue Tracking, Third Party Advisory]
https://www.usenix.org/conference/usenixsecurity21/presentation/kirzner [Third Party Advisory]

Authoritative record: CVE-2021-33624 at cve.org

Weaknesses: CWE-843

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2021-33624 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.