What is CVE-2021-3910?

CVE-2021-3910 is a medium-severity vulnerability in Cloudflare Octorpki, classified under Improper Input Validation. CVSS score: 4.4/10. Published 2021-11-11.

How severe is CVE-2021-3910?

Medium severity. CVSS v3 base score is 4.4 out of 10.

Improper input validation in Cloudflare Octorpki

CVE-2021-3910

OctoRPKI crashes when encountering a repository that returns an invalid ROA (just an encoded NUL (\0) character).

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

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

CVSS v3 metric

CVSS v3 base score 4.4 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.013 (69.2th percentile), scored 2026-09-29.

Low probability of exploitation in the next 30 days, but still tracked. 69th percentile — 69.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.013 · newest: 0.013 · change: +0.000

Affected products

Cloudflare Octorpki — versions unspecified
Debian Linux — versions 11.0

Weakness classification (CWE)

CWE-20 — Improper Input Validation

References

github.com/cloudflare/cfrpki/security/advisories/GHSA-5mxh-2qfv-4g7j (Third Party Advisory)
www.debian.org/security/2022/dsa-5041 (vendor-advisory, Third Party Advisory)

Frequently asked questions

What is CVE-2021-3910?: CVE-2021-3910 is a medium-severity vulnerability in Cloudflare Octorpki, classified under Improper Input Validation. CVSS score: 4.4/10. Published 2021-11-11.
How severe is CVE-2021-3910?: Medium severity. CVSS v3 base score is 4.4 out of 10.