PrivateBin is missing HTML sanitization of attached filename in file size hint

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

5.8 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N

EPSS

• CVE-2025-62796: 0.29% estimated exploitation activity in the next 30 days; percentile 22.21 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

We’ve identified an HTML injection/XSS vulnerability in PrivateBin service that allows the injection of arbitrary HTML markup via the attached filename. Below are the technical details, PoC, reproduction steps, impact, and mitigation recommendations. Recommend action: As the vulnerability has been fixed in the latest version, users are strongly encouraged to upgrade PrivateBin to the latest version and check that a strong CSP header, just as the default suggested one, is delivered. Summary of the vulnerability: The attachmentname field containing the attached file name is included in the object that the client encrypts and is eventually rendered in the DOM without proper escaping. Impact The vulnerability allows attackers to inject arbitrary HTML into the filename displayed near the file size hint, when attachments are enabled. This is by definition a XSS vulnerability (CWE-80), in this case even a persistent XSS. As any HTML can be injected, basically, this can e.g. be used to…

Published by the source

28 Oct 2025, 20:14 UTC

Last modified by the source

29 Oct 2025, 14:49 UTC

Source last checked

26 Oct 2026, 14:34 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-867c-p784-5q6g

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# Patch Next advisory brief: CVE-2025-62796

Advisory: PrivateBin is missing HTML sanitization of attached filename in file size hint
IDs: CVE-2025-62796, GHSA-867c-p784-5q6g
Record: https://patchnext.com/advisories/cve-2025-62796 (revision 1, source checked 26 Oct 2026, 14:34 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.8)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: privatebin/privatebin 2.0.2. A vendor fix does not mean a deployment is fixed.

## Affected components
- Packagist privatebin/privatebin: affected >= 1.7.7, < 2.0.2; fixed in 2.0.2

## Suggested inspection (read-only)
- Packagist privatebin/privatebin: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on privatebin/privatebin.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-867c-p784-5q6g (GitHub-reviewed advisory GHSA-867c-p784-5q6g lists affected ranges: Packagist privatebin/privatebin >=1.7.7 <2.0.2)

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