What is CVE-2021-3911?

CVE-2021-3911 is a medium-severity vulnerability in Cloudflare Octorpki, classified under Improper Input Validation. CVSS score: 4.2/10. Published 2021-11-11.

How severe is CVE-2021-3911?

Medium severity. CVSS v3 base score is 4.2 out of 10.

Improper input validation in Cloudflare Octorpki

CVE-2021-3911

If the ROA that a repository returns contains too many bits for the IP address then OctoRPKI will crash.

Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)

Published 2021-11-11 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 4.2 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.009 (58.3th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 58th percentile — 58.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.009 · newest: 0.009 · change: +0.000

Affected products

Cloudflare Octorpki — versions unspecified
Debian Linux — versions 11.0

Weakness classification (CWE)

References

github.com/cloudflare/cfrpki/security/advisories/GHSA-w6ww-fmfx-2x22 (Third Party Advisory)
www.debian.org/security/2022/dsa-5041 (vendor-advisory, Third Party Advisory)

Frequently asked questions

What is CVE-2021-3911?: CVE-2021-3911 is a medium-severity vulnerability in Cloudflare Octorpki, classified under Improper Input Validation. CVSS score: 4.2/10. Published 2021-11-11.
How severe is CVE-2021-3911?: Medium severity. CVSS v3 base score is 4.2 out of 10.