CVE-2021-3163

Severity: medium (CVSS 6.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.3% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2021-04-12 · updated 2026-06-17
Weakness: CWE-79

Description

A vulnerability in the HTML editor of Slab Quill 4.8.0 allows an attacker to execute arbitrary JavaScript by storing an XSS payload (a crafted onloadstart attribute of an IMG element) in a text field. Note: Researchers have claimed that this issue is not within the product itself, but is intended behavior in a web browser

Affected products

Slab Quill: 4.8.0

References

https://burninatorsec.blogspot.com/2021/04/cve-2021-3163-xss-slab-quill-js.html
https://github.com/quilljs/quill/issues/3273
https://github.com/quilljs/quill/issues/3364
https://quilljs.com
https://burninatorsec.blogspot.com/2021/04/cve-2021-3163-xss-slab-quill-js.html
https://github.com/quilljs/quill/issues/3273
https://github.com/quilljs/quill/issues/3364
https://quilljs.com

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