What is CVE-2020-8288?

CVE-2020-8288 is a medium-severity vulnerability in Rocket.chat, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2021-01-26.

How severe is CVE-2020-8288?

Medium severity. CVSS v3 base score is 5.4 out of 10.

XSS in Rocket.chat

CVE-2020-8288

The `specializedRendering` function in Rocket.Chat server before 3.9.2 allows a cross-site scripting (XSS) vulnerability by way of the `value` parameter.

Vulnerability class: XSS (Cross-Site Scripting)

Published 2021-01-26 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.008 (56.6th percentile), scored 2026-10-03.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 57th percentile — 56.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.008 · newest: 0.008 · change: 0.000

Affected products

Rocket.chat
Rocket.chat Server — versions Fixed in 3.9.2

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

hackerone.com/reports/899954 (Exploit, Third Party Advisory)
rocket.chat/xss-vulnerability-hotfix-available-for-all-affected-versions/ (Patch, Vendor Advisory)
docs.rocket.chat/guides/security/security-updates (Vendor Advisory)

Frequently asked questions

What is CVE-2020-8288?: CVE-2020-8288 is a medium-severity vulnerability in Rocket.chat, classified under Cross-site Scripting. CVSS score: 5.4/10. Published 2021-01-26.
How severe is CVE-2020-8288?: Medium severity. CVSS v3 base score is 5.4 out of 10.