CVE-2026-69201
mediumHttp4s is a Scala interface for HTTP services.
Http4s 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.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N Affected products
Not reported by the source (unknown — not "none").
Weakness classification (CWE)
Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.
Mitigation & advisories
No vendor advisory or patch reference tagged by NVD. Check the references below.
References
- https://github.com/http4s/http4s/commit/bcd99cdc1342ef58a0f132acb814af06a668a8d3 security-advisories@github.com
- https://github.com/http4s/http4s/releases/tag/v0.23.35 security-advisories@github.com
- https://github.com/http4s/http4s/releases/tag/v1.0.0-M47 security-advisories@github.com
- https://github.com/http4s/http4s/security/advisories/GHSA-crq5-92j2-j7wv security-advisories@github.com