What is CVE-2021-34816?

CVE-2021-34816 is a high-severity vulnerability in Etherpad, classified under Argument Injection. CVSS score: 7.2/10. Published 2021-07-21.

How severe is CVE-2021-34816?

High severity. CVSS v3 base score is 7.2 out of 10.

Vulnerability in Etherpad

CVE-2021-34816

An Argument Injection issue in the plugin management of Etherpad 1.8.13 allows privileged users to execute arbitrary code on the server by installing plugins from an attacker-controlled source.

Published 2021-07-21 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.2 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.022 (82.1th percentile), scored 2026-10-01.

Low probability of exploitation in the next 30 days, but still tracked. 82nd percentile — 82.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.022 · newest: 0.022 · change: 0.000

Affected products

Etherpad — versions 1.8.13

Weakness classification (CWE)

CWE-88 — Argument Injection

References

github.com/ether/etherpad-lite/releases (Third Party Advisory, Release Notes)
blog.sonarsource.com/etherpad-code-execution-vulnerabilities (Exploit, Third Party Advisory)

Frequently asked questions

What is CVE-2021-34816?: CVE-2021-34816 is a high-severity vulnerability in Etherpad, classified under Argument Injection. CVSS score: 7.2/10. Published 2021-07-21.
How severe is CVE-2021-34816?: High severity. CVSS v3 base score is 7.2 out of 10.