CVE-2026-78381 RansomLook Arbitrary File Read via Path Traversal in Post screen Field
An attacker with admin access or control over imported data can read arbitrary files via path traversal in the post screen field, exposing sensitive configuration and credentials.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-78381?
CVE-2026-78381 is a high-severity path traversal vulnerability in ransomlook, published on 24 Aug 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Official description
RansomLook contains a path traversal vulnerability in the handling of the screen field associated with group posts. The GroupPost.get API handler concatenates the database-controlled screen value directly with the application's source/ directory and opens the resulting path without verifying that the resolved file remains within the intended directory.
Because the screen field is free-form and can be populated either through the administrative post editor or through data imported from a remote RansomLook instance, a malicious upstream instance can provide traversal sequences such as ../config/generic.json. When the affected post is subsequently retrieved through the API, RansomLook resolves and reads the attacker-controlled path and returns the contents of the referenced file Base64-encoded in the API response.
This can allow an attacker (being admin) controlling imported post data to read arbitrary files accessible to the RansomLook process, potentially exposing sensitive configuration data, API credentials, password hashes, or other application secrets. The attack does not require the malicious upstream to possess an account on the affected RansomLook instance.
The vulnerability is addressed by resolving screen paths with os.path.realpath() and verifying that the resolved path remains beneath the application's source/ directory. Validation is performed both when values are written and immediately before files are read. Using canonical paths also prevents traversal through symbolic links that would bypass purely lexical path normalization checks.
Weakness: CWE-22
Which versions are affected by CVE-2026-78381?
How do I fix CVE-2026-78381?
No fix has been published for CVE-2026-78381 yet. Limit exposure of the affected software until one is available.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2026-78381 being exploited?
There is no known exploitation of CVE-2026-78381 in the wild and no public exploit code.
Sources
Also known as GHSA-8f7x-5f58-rfpw.