CVE-2026-55696

4.3 MEDIUM 0.4% exploit odds Fix listed XSS Server

What it is

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.

At a glance

Exploitability: Can be exploited over the network without logging in, but needs a user to act. Limited direct impact.
Exploit odds: 0.4% chance of exploitation in the next 30 days (EPSS).
Fix: A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

2026-08-28 22:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2026-09-09 21:09 UTC Last updatedMost recent change to the record

Why it ranks here

Exploited in the wild: no, CISA does not list it.
Exploit odds: 0.4% in the next 30 days (EPSS).
Severity: 4.3 MEDIUM (CVSS).
Fix: a patch or advisory is linked.

Details

Published: 2026-08-28 22:16 UTC
Last modified: 2026-09-09 21:09 UTC
Exploit probability: 0.4% · EPSS, next 30 days
Weakness: CWE-79 · Cross-site scripting
Record status: Deferred

Attack profile CVSS 3.1 · 4.3

Attack vector: Network
Complexity: Low
Privileges needed: None
User interaction: Required
Scope: Unchanged
Confidentiality: Low
Integrity: None
Availability: None

Raw vector

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

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-55696.md and follow it. Check whether this project is affected by CVE-2026-55696. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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Fix and advisories

References

NVD record · CVE.org record