yawsconfig.erl in Yaws through 2.0.2 and/or 2.0.7 loads obsolete TLS ciphers, as demonstrated by ones that allow Sweet32 attacks, if running on an Erlang/OTP virtual machine with a version less than 21.0.

Yaws 1.91 allows Unauthenticated Remote File Disclosure via HTTP Directory Traversal with /%5C../ to port 8080. NOTE: this CVE is only about use of an initial /%5C sequence to defeat traversal protection mechanisms; the initial /%5C sequence was apparently not discussed in earlier research on this product.

Multiple cross-site scripting (XSS) vulnerabilities in the wiki application in Yaws 1.88 allow remote attackers to inject arbitrary web script or HTML via (1) the tag parameter to editTag.yaws, (2) the index parameter to showOldPage.yaws, (3) the node parameter to allRefsToMe.yaws, or (4) the text parameter to editPage.yaws.

Yaws 1.85 writes data to a log file without sanitizing non-printable characters, which might allow remote attackers to modify a window's title, or possibly execute arbitrary commands or overwrite files, via an HTTP request containing an escape sequence for a terminal emulator.