CVE-2023-36459 CRITICAL

CVE-2023-36459: Mastodon vulnerable to Cross-site Scripting through oEmbed preview cards

Vendor Mastodon
Product mastodon
Weakness CWE-79 · XSS
Published July 6, 2023
Last update February 13, 2025
View on NVD All CVEs

CVSS base score

9.3/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction Required
Confidentiality High
Integrity High

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

July 6, 2023 CVE published
February 13, 2025 Record updated