CVE-2020-29456
MEDIUMCVE-2020-29456 is a medium-severity (CVSS 6.1) Cross-site Scripting (XSS) vulnerability in papermerge. O3 Security confirms whether CVE-2020-29456 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Cross-site scripting in papermerge
Real-World Exposure
papermergeReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
Multiple cross-site scripting (XSS) vulnerabilities in Papermerge before 1.5.2 allow remote attackers to inject arbitrary web script or HTML via the rename, tag, upload, or create folder function. The payload can be in a folder, a tag, or a document's filename. If email consumption is configured in Papermerge, a malicious document can be sent by email and is automatically uploaded into the Papermerge web application. Therefore, no authentication is required to exploit XSS if email consumption is configured. Otherwise authentication is required.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | papermerge | ≥ 1.2.0&&< 1.5.2 | 1.5.2 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for papermerge. 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 papermerge to 1.5.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-29456 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-2020-29456 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-2020-29456. 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-2020-29456 in your dependencies?
O3 detects CVE-2020-29456 across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.