What is CVE-2018-6835?

CVE-2018-6835 is a critical-severity vulnerability in Etherpad, classified under Improper Input Validation. CVSS score: 9.8/10. Published 2018-02-08.

How severe is CVE-2018-6835?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Is CVE-2018-6835 known to be exploited?

4 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Improper input validation in Etherpad

CVE-2018-6835

node/hooks/express/apicalls.js in Etherpad Lite before v1.6.3 mishandles JSONP, which allows remote attackers to bypass intended access restrictions.

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

Published 2018-02-08 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.023 (82.5th percentile), scored 2026-09-30.

Low probability of exploitation in the next 30 days, but still tracked. 83rd percentile — 82.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.023 · newest: 0.023 · change: 0.000

Affected products

Etherpad

Weakness classification (CWE)

CWE-20 — Improper Input Validation

Public proof-of-concept exploits

References

github.com/ether/etherpad-lite/releases/tag/1.6.3 (Third Party Advisory, Release Notes)
github.com/ether/etherpad-lite/commit/626e58cc5af1db3691b41fca7b06c28ea43141b1 (Patch, Third Party Advisory)

Frequently asked questions

What is CVE-2018-6835?: CVE-2018-6835 is a critical-severity vulnerability in Etherpad, classified under Improper Input Validation. CVSS score: 9.8/10. Published 2018-02-08.
How severe is CVE-2018-6835?: Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2018-6835 known to be exploited?: 4 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.