CVE-2023-36459
Mastodon vulnerable to Cross-site Scripting through oEmbed preview cards
Description
Mastodon is a free, open-source social network server based on ActivityPub. Starting in version 1.3 and prior to versions 3.5.9, 4.0.5, and 4.1.3, an attacker using carefully crafted oEmbed data can bypass the HTML sanitization performed by Mastodon and include arbitrary HTML in oEmbed preview cards. This introduces a vector for cross-site scripting (XSS) payloads that can be rendered in the user's browser when a preview card for a malicious link is clicked through. Versions 3.5.9, 4.0.5, and 4.1.3 contain a patch for this issue.
How to fix CVE-2023-36459
To remediate CVE-2023-36459, upgrade the affected package to a fixed version below.
- —upgrade to 3.5.9 or later
Is CVE-2023-36459 being exploited?
Low — EPSS is 0.2%, meaning exploitation activity has not been observed at scale.
Affected packages (1)
- >= 1.3.0, < 3.5.9, >= 4.0.0, < 4.0.5, >= 4.1.0, < 4.1.3
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | MEDIUM6.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N |