CVE-2026-90774

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.

References

• https://github.com/orhun/rustypaste
• https://github.com/orhun/rustypaste/blob/v0.18.0/src/paste.rs
• https://github.com/orhun/rustypaste/commit/ac05d552596af4a8429d80f30d11f67117ce02c8
• https://github.com/orhun/rustypaste/issues/622
• https://www.vulncheck.com/advisories/rustypaste-before-0.18.1-path-traversal-via-filename-header