CVE-2026-48822: 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...

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.

Metrics

CVSS 3.1

5.8/10

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

EPSS Probability

0.12%

2.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-79

References

Timeline

Published: Jun 17, 2026
Last Modified: Jun 18, 2026
Status: Deferred

Frequently Asked Questions

What is CVE-2026-48822?

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.

How severe is CVE-2026-48822?

CVE-2026-48822 has a CVSS score of 5.8/10 (MEDIUM severity). The EPSS model estimates a 0.12% probability of exploitation in the next 30 days.

How do I fix CVE-2026-48822?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.