XSS in Scratchaddons Scratch Addons
CVE-2020-26239
Scratch Addons is a WebExtension that supports both Chrome and Firefox. Scratch Addons before version 1.3.2 is vulnerable to DOM-based XSS. If the victim visited a specific website, the More Links addon of the Scratch Addons extension used incorrect regular expression which caused the HTML-escaped values to be unescaped, leading to XSS. Scratch Addons version 1.3.2 fixes the bug. The extension will be automatically updated by the browser. More Links addon can be disabled via the option of the extension.
Vulnerability class: XSS (Cross-Site Scripting)
EPSS: 0.010 (59.7th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.6 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:H/A:N.
Affected products
- Scratchaddons Scratch_addons
- Scratchaddons — versions < 1.3.2
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Patch, Third Party Advisory)
- security-advisories@github.com (Patch, Third Party Advisory, x_refsource_MISC)
- security-advisories@github.com (Third Party Advisory, x_refsource_MISC)
- security-advisories@github.com (Third Party Advisory, x_refsource_MISC, Release Notes)
Frequently asked questions
- What is CVE-2020-26239?
- CVE-2020-26239 is a high-severity vulnerability in Scratchaddons Scratch Addons, classified under Cross-site Scripting. CVSS score: 7.6/10. Published 2020-11-23.
- How severe is CVE-2020-26239?
- High severity. CVSS v3 base score is 7.6 out of 10.