CVE-2026-69201

Http4s: ResourceService and Webjar Service path escape via percent-encoded separators

Published Sep 15, 2026 CVSS 3.1 · 5.9 Medium EPSS < 1% KEV · Not listed
Description
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-crq5-92j2-j7wv Http4s: ResourceService and Webjar Service path escape via percent-encoded separators
History
Type Values Removed Values Added
First Time appeared Http4s
Http4s http4s
Vendors & Products Http4s
Http4s http4s
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description 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.
Title Http4s: ResourceService and Webjar Service path escape via percent-encoded separators
Weaknesses CWE-22
References
Metrics cvssV3_1

{'score': 5.9, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Sep 15, 2026, 7:21 PM
Reserved
Aug 3, 2026, 4:57 PM
Status
Deferred
Published
Sep 15, 2026, 7:17 PM
Modified
Sep 16, 2026, 8:38 PM