CVE-2025-62796
MEDIUMCVE-2025-62796 is a medium-severity (CVSS 5.8) Cross-site Scripting (XSS) vulnerability in privatebin/privatebin. O3 Security confirms whether CVE-2025-62796 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
PrivateBin persistent HTML injection in attachment filename enables redirect and defacement
Blast Radius
privatebin/privatebinReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
PrivateBin is an online pastebin where the server has zero knowledge of pasted data. Versions 1.7.7 through 2.0.1 allow persistent HTML injection via the unsanitized attachment filename (attachment_name) when attachments are enabled. An attacker can modify attachment_name before encryption so that, after decryption, arbitrary HTML is inserted unescaped into the page near the file size hint, enabling redirect (e.g., meta refresh) and site defacement and related phishing attacks. Script execution is normally blocked by the recommended Content Security Policy, limiting confidentiality impact. The issue was introduced in 1.7.7 and fixed in 2.0.2. Update to 2.0.2 or later. Workarounds include enforcing the recommended CSP, deploying PrivateBin on a separate domain, or disabling attachments.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | privatebin/privatebin | ≥ 1.7.7&&< 2.0.2 | 2.0.2 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for privatebin/privatebin. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update privatebin/privatebin to 2.0.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-62796 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2025-62796 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2025-62796. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2025-62796 in your dependencies?
O3 detects CVE-2025-62796 across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.