Executive brief
SecureDrop Client is a desktop application used by journalists to securely communicate with sources and manage confidential submissions. A malicious SecureDrop Server could bypass the proxy's origin restrictions by sending cross-origin redirects, potentially exposing the journalist's connection to unintended servers. This vulnerability requires the server itself to be previously compromised, and the impact is limited because the proxy does not handle plaintext communications.
Technical details
The vulnerability exists in securedrop-proxy, a component that restricts requests between the SecureDrop Inbox (sd-app VM) and the configured SecureDrop Server. The proxy was following HTTP redirects by default (via reqwest and python-requests libraries) without validating redirect target origins. A compromised SecureDrop Server could respond with a cross-origin redirect, causing the proxy to send subsequent requests to an attacker-controlled server. The SecureDrop Server API does not require redirects for any legitimate operation. The fix disables redirect following entirely. Exploitation requires a previously compromised SecureDrop Server, which itself is hardened as a dedicated physical machine exposed only via Tor hidden services; therefore real-world exploitability is low.
Affected products
- Freedom of the Press SecureDrop Client prior to 1.3.1
Timeline
- 2026-05-28: disclosed: Advisory published on GitHub
- 2026-05-28: patched: Version 1.3.1 released with fix
- 2026-08-20: advisory: CVE-2026-49996 published