CVE-2026-78553: RansomLook created its Flask session-signing key without explicitly restricting the file permissions.

RansomLook created its Flask session-signing key without explicitly restricting the file permissions.

RansomLook created its Flask session-signing key without explicitly restricting the file permissions. The secret_key file was created using the process's default permissions and umask, resulting in permissions such as 0644 under a common 022 umask. Consequently, other local users able to access the RansomLook home directory could read the application's cryptographic secret. The exposed key is security-critical because it is used to sign Flask session cookies and is also involved in the legacy API-key key derivation. An attacker who obtains the key can generate valid session cookies and impersonate an authenticated user, including an administrator. In LDAP configurations, exploitation may be particularly straightforward because the session user loader does not require the supplied username to correspond to an existing local user. Successful exploitation requires local access sufficient to read the improperly protected file, but can result in complete compromise of RansomLook's authentication and authorization controls. The patch creates new secret-key files atomically with permissions 0600 and also restricts permissions on existing key files during application startup.

Description from the National Vulnerability Database, published by 5a6e4751-2f3f-4070-9419-94fb35b644e8

What it means for a small business

If your business uses ransomlook, install the vendor's update. If you're not sure whether you use it, ask whoever manages your computers.

How likely is an attack? The Exploit Prediction Scoring System, run by FIRST (the global association of security response teams), puts the odds of this one being exploited in the next 30 days at 0.19%, higher than 9% of CVEs. That’s low, but low isn’t zero, and the odds jump the day someone publishes an exploit. Scored October 28, 2026, updated daily.

Check your own setup

Website check: reads what your site runs from the outside (WordPress version, plugins it can see, old server software) and matches it against this database.
Server check: what your web server says about itself, and whether that version has known flaws.

Sources

Part of the Huttenlocher Technologies vulnerability database, refreshed twice a day from CISA and the NVD. The title, category and plain-language guidance are ours; check the linked record before acting on a detail. This is general guidance, not a review of your systems.

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