Published: September 22, 2026 | Last Modified: September 22, 2026
Dancer2 versions from 2.1.0 before 2.2.0 for Perl serve files from outside public_dir via relative path segments in the File route handler. The handler joins the request path onto public_dir without collapsing relative segments, and checks only that the result is a readable regular file. A request for `/../outside.txt` escapes public_dir, and percent-encoding the dots reaches the same file. The handler is off by default. An application is affected once it names File in route_handlers and sets static_handler to 0, which otherwise refuses a dot segment before the route runs. Any file the worker process can read is served to an unauthenticated request, including the application's config.yml above public_dir.
Exploitation Probability (EPSS): Low — 0.19% (9th percentile)
Low exploitation probability based on current threat landscape data. Standard patching timeline is appropriate.
This analysis is generated by Ghostwire from NVD, CISA KEV, EPSS, and open-source intelligence data. Verify findings through primary sources before acting.