CVE-2026-90774 rustypaste before 0.18.1 Path Traversal via filename header
Attackers can write files to arbitrary locations outside the upload directory by exploiting path traversal in the filename header when custom filenames are enabled.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-90774?
CVE-2026-90774 is a high-severity path traversal vulnerability in orhun rustypaste, published on 13 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
rustypaste before 0.18.1 validates the destination path before applying the optional custom filename HTTP header, allowing attackers to bypass directory-escape checks. Attackers can supply path traversal sequences in the filename header to write files outside the configured upload directory to arbitrary locations.
Weakness: CWE-22
Which versions are affected by CVE-2026-90774?
How do I fix CVE-2026-90774?
No fix has been published for CVE-2026-90774 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-2026-90774 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-90774 exists.
Public exploit code: 1 Nuclei template.
Sources
Also known as GHSA-jcjc-q6x9-fww9.