What is CVE-2021-47784?

CVE-2021-47784 is a high-severity vulnerability in Cyberfox Web Browser, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 7.5/10. Published 2026-01-15.

How severe is CVE-2021-47784?

High severity. CVSS v3 base score is 7.5 out of 10.

Resource exhaustion in Cyberfox Web Browser

CVE-2021-47784

Cyberfox Web Browser 52.9.1 contains a denial of service vulnerability that allows attackers to crash the application by overflowing the search bar with excessive data. Attackers can generate a 9,000,000 byte payload and paste it into the…

EPSS: 0.002 (10.0th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

Cyberfox Web Browser — versions 52.9.1 (Possibly all versions)

Weakness classification (CWE)

CWE-770 — Allocation of Resources Without Limits or Throttling

References

disclosure@vulncheck.com (exploit)
disclosure@vulncheck.com (product)

Frequently asked questions

What is CVE-2021-47784?: CVE-2021-47784 is a high-severity vulnerability in Cyberfox Web Browser, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 7.5/10. Published 2026-01-15.
How severe is CVE-2021-47784?: High severity. CVSS v3 base score is 7.5 out of 10.