CVE-2026-57957 Papermark 0.22.0 - CORS Misconfiguration in Viewer Upload Endpoint
Attackers can exploit CORS misconfiguration to upload files and read data from victim datarooms via credentialed cross-origin requests.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-57957?
CVE-2026-57957 is a low-severity vulnerability in papermark, published on 29 Jun 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
Papermark through 0.22.0 contains a cross-origin resource sharing (CORS) misconfiguration vulnerability that allows unauthenticated remote attackers to perform credentialed cross-origin requests by exploiting the TUS-based viewer upload endpoint reflecting arbitrary request Origins with Access-Control-Allow-Credentials set to true. Attackers can lure authenticated victims to malicious pages that silently issue credentialed cross-origin requests to upload arbitrary files into victim datarooms and read credentialed responses.
Weakness: CWE-942
Which versions are affected by CVE-2026-57957?
How do I fix CVE-2026-57957?
No fix has been published for CVE-2026-57957 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-57957 being exploited?
There is no known exploitation of CVE-2026-57957 in the wild and no public exploit code.
Sources
Also known as GHSA-4cq7-5c7c-cc5r.