CVE-2026-35200
MEDIUMParse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to 8.6.73 and 9.7.1-alpha.4, a file can be uploaded with a filename extension…
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Description
Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to 8.6.73 and 9.7.1-alpha.4, a file can be uploaded with a filename extension that passes the file extension allowlist (e.g., .txt) but with a Content-Type header that differs from the extension (e.g., text/html). The Content-Type is passed to the storage adapter without consistency validation. Storage adapters that store and serve the provided Content-Type (such as S3 or GCS) serve the file with the mismatched Content-Type. The default GridFS adapter is not affected because it derives Content-Type from the filename at serving time. This vulnerability is fixed in 8.6.73 and 9.7.1-alpha.4.
Affected Products
parse-serverparseplatformDetection & mitigation playbook
Vendor / applianceDetect
Inventory every parseplatform parse-server deployment and check each version against the affected-products list above. Because the exploit targets the running system rather than your application code, also watch for exploitation at the network and runtime layer — O3 flags the exploit behaviour from runtime telemetry and egress traffic even before a vulnerable build is confirmed.
Fix
Apply the parseplatform parse-server security patch or hotfix for CVE-2026-35200 on the affected version, following the vendor advisory for your exact build.
Workarounds
Cut exposure now: restrict the management/admin interface to trusted networks, segment the device, and apply the vendor's recommended configuration mitigations and any WAF/IPS signature. O3's runtime protection blocks the exploit chain at execution, holding the line on unpatched or end-of-life systems until you can patch.
How O3 protects you
O3 detects and blocks CVE-2026-35200 exploitation at runtime: eBPF exploit-chain detection, plus L7 egress monitoring that catches the post-exploitation callback and severs the attacker's outbound channel.
Tailored to CVE-2026-35200. 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-2026-35200 being exploited in your environment?
O3's eBPF runtime sensors and L7 egress monitoring detect and block the CVE-2026-35200 exploit chain at execution — protecting unpatched and end-of-life systems until the vendor patch is applied.