23 Oct 2026 15:48:27 UTC
Http4s: ResourceService and Webjar Service path escape via percent-encoded separators
cve-program · CVE-2026-69201 · Published
CVE-2026-69201
Http4s: ResourceService and Webjar Service path escape via percent-encoded separators
CVSS 3.1 5.9 MEDIUMCheck source for fixed versionsKEV status unknown
cve-program · CVE-2026-69201
PublishedHttp4s is a Scala interface for HTTP services. Prior to 0.23.35 and 1.0.0-M47, ResourceService and WebjarService decode each URL path segment but reject only segments exactly equal to an empty string, a dot, or two dots. A request containing percent-encoded slash or backslash separators can turn an accepted segment into a parent-directory traversal after decoding, allowing access to classpath or WebJar resources outside the configured base when a directory-backed classpath is served and the backend preserves the encoded separator. The patch rejects decoded segments containing slash or backslash in ResourceService and WebjarService, and applies the same guard to the non-exploitable FileService for consistency. This issue is fixed in versions 0.23.35 and 1.0.0-M47.
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