VulnerabilityDeferred

CVE-2026-48822

Versions 0.16.1 and prior contain a stored Cross-Site Scripting (XSS) vulnerability in the Markdown-to-HTML conversion process used in the Bookmark Description field.

MEDIUM 5.8EPSS 0.12%

Does this matter?

Lower severity and a low EPSS score (0.12%). Track it; it rarely justifies an emergency change on its own.

Description

Shaarli is a personal bookmarking service. Versions 0.16.1 and prior contain a stored Cross-Site Scripting (XSS) vulnerability in the Markdown-to-HTML conversion process used in the Bookmark Description field. An authenticated user can inject a malicious javascript: URI inside a Markdown link. The vulnerability originates in the filterProtocols method within BookmarkMarkdownFormatter.php.This method attempts to sanitize Markdown links by filtering dangerous protocols (such as javascript:) before rendering. It uses the following regular expression: (#]\((.*?)\)#is). This regex is designed to detect inline Markdown links, but it fails to detect Markdown reference-style links because reference-style links are resolved by the Markdown parser after preprocessing. The filterProtocols method never inspects the actual URL used in these references and as a result, an attacker can supply a javascript: URI inside a reference definition. This issue has been fixed in version 0.16.2.

CVSS 3.1: 5.8 MEDIUMCVSS:3.1/AV:L/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:N
EPSS: 0.12% probability · 2th percentile
CISA KEV: Not listed
Weakness: CWE-79
Source: security-advisories@github.com

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.