What is CVE-2020-18221?

CVE-2020-18221 is a medium-severity vulnerability in Typora, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2021-05-26.

How severe is CVE-2020-18221?

Medium severity. CVSS v3 base score is 6.1 out of 10.

XSS in Typora

CVE-2020-18221

Cross Site Scripting (XSS) in Typora v0.9.65 and earlier allows remote attackers to execute arbitrary code by injecting commands during block rendering of a mathematical formula.

Vulnerability class: XSS (Cross-Site Scripting)

Published 2021-05-26 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.012 (66.5th percentile), scored 2026-09-30.

Low probability of exploitation in the next 30 days, but still tracked. 67th percentile — 66.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.012 · newest: 0.012 · change: 0.000

Affected products

Typora

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

github.com/typora/typora-issues/issues/2204 (Exploit, Third Party Advisory, Issue Tracking)

Frequently asked questions

What is CVE-2020-18221?: CVE-2020-18221 is a medium-severity vulnerability in Typora, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2021-05-26.
How severe is CVE-2020-18221?: Medium severity. CVSS v3 base score is 6.1 out of 10.