CVE-2026-48822

CVE-2026-48822 is a medium-severity vulnerability with a CVSS 3.x base score of 5.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-79.

Key facts

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.

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 3.x base score of 5.8, rated medium severity. It is exploitable over local access with low attack complexity, requires high privileges and user interaction. Impact on confidentiality is high, integrity high, and availability none.
Is CVE-2026-48822 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (2nd percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-48822?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-48822 have an EU (EUVD) identifier?
Yes. CVE-2026-48822 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-37791.
When was CVE-2026-48822 published?
CVE-2026-48822 was published on 2026-06-17 and last updated on 2026-06-18.

References

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