Vulnerability Description
PrivateBin is an online pastebin where the server has zero knowledge of pasted data. Prior to 2.0.5, AttachmentViewer.setAttachment in js/privatebin.js uses getAttachmentMimeType to accept attacker-controlled MIME types and uses getBlobUrl to create a same-origin blob before setting attachmentLink's href for the Download attachment link. The SVG-only sanitization branch updates only the preview blob, so text/html, image/svg, application/xhtml+xml, and text/xml attachments can remain active in the download blob. On an instance with fileupload = true and a weakened, stripped, or absent Content Security Policy, an anonymous attacker can create such an attachment, and a victim who opens the link in a new tab causes inline JavaScript to execute in the PrivateBin origin. The script can read origin-scoped local storage and issue same-origin requests, including requests to applications co-hosted on the same domain. This issue is fixed in version 2.0.5.
CVSS Score
MEDIUM
Related Weaknesses (CWE)
References
- https://github.com/PrivateBin/PrivateBin/commit/7f1f40853efe0eb12db9cc4a30ea8524
- https://github.com/PrivateBin/PrivateBin/releases/tag/2.0.5
- https://github.com/PrivateBin/PrivateBin/security/advisories/GHSA-f2xf-7x3g-4272
FAQ
What is CVE-2026-55696?
CVE-2026-55696 is a vulnerability with a CVSS score of 4.3 (MEDIUM). PrivateBin is an online pastebin where the server has zero knowledge of pasted data. Prior to 2.0.5, AttachmentViewer.setAttachment in js/privatebin.js uses getAttachmentMimeType to accept attacker-co...
How severe is CVE-2026-55696?
CVE-2026-55696 has been rated MEDIUM with a CVSS base score of 4.3/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-55696?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.