CVE-2021-20727 json
Cross-site scripting vulnerability in Zettlr from 0.20.0 to 1.8.8 allows an attacker to execute an arbitrary script by loading a file or co…
published 2021-05-27 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-8141
- cvss
- 6.1
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 1.0%
- EPSS 1.0% chance of exploitation in 30 days, percentile 64%
- public exploits
- 0
- none known
Summary
Cross-site scripting vulnerability in Zettlr from 0.20.0 to 1.8.8 allows an attacker to execute an arbitrary script by loading a file or code snippet containing an invalid iframe into Zettlr.
Exploit prediction
1.04% chance of exploitation in the next 30 days, higher than 64% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.1 | 6.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N |
| NVD | 2.0 | 4.3 | AV:N/AC:M/Au:N/C:N/I:P/A:N |
Affected products
- Hendrik Erz Zettlr
Classification
- Weakness
-
- CWE-79 Improper Neutralization of Input During Web Page Generation
References
-
zettlr.com
/
product
-
github.com
/Zettlr/Zettlr
third-party-advisory
-
jvn.jp
/en/jp/JVN98239374/index.html
third-party-advisory
Sources
- CVE List CVE-2021-20727
- NVD CVE-2021-20727
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.