What is CVE-2020-21058?

CVE-2020-21058 is a medium-severity vulnerability in Typora, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2023-06-20.

How severe is CVE-2020-21058?

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

XSS in Typora

CVE-2020-21058

Cross Site Scripting vulnerability in Typora v.0.9.79 allows a remote attacker to execute arbitrary code via the mermaid sytax.

Vulnerability class: XSS (Cross-Site Scripting)

Published 2023-06-20 · 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: 0.006 (45.1th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 45th percentile — 45.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: 0.000

Affected products

Typora — versions 0.9.79

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

github.com/typora/typora-issues/issues/2959 (Exploit, Patch, Issue Tracking)

Frequently asked questions

What is CVE-2020-21058?: CVE-2020-21058 is a medium-severity vulnerability in Typora, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2023-06-20.
How severe is CVE-2020-21058?: Medium severity. CVSS v3 base score is 6.1 out of 10.