Vulnerability Description
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.
CVSS Score
HIGH
Related Weaknesses (CWE)
References
- https://github.com/PerlDancer/Dancer2/commit/2446a09ffb83fef71cc75c327bd6e4b1f00
- https://github.com/PerlDancer/Dancer2/security/advisories/GHSA-6xw8-v24c-m783
- https://metacpan.org/release/CROMEDOME/Dancer2-2.2.0/changes
- http://www.openwall.com/lists/oss-security/2026/09/22/4
FAQ
What is CVE-2026-93712?
CVE-2026-93712 is a vulnerability with a CVSS score of 7.5 (HIGH). 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 ...
How severe is CVE-2026-93712?
CVE-2026-93712 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-93712?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.