Is CVE-2026-34786 actively exploited?

CVE-2026-34786 has no public evidence of in-the-wild exploitation as of 2026-04-16.

What is the CVSS score for CVE-2026-34786?

CVE-2026-34786 has a CVSS score of 5.3 (MEDIUM severity). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N.

How do I patch CVE-2026-34786?

Patch guidance is available from rack security advisories. CVEDatabase generates AI-assisted remediation guidance on demand for CVE-2026-34786.

Which products are affected by CVE-2026-34786?

3 products: rack rack, rack rack, rack rack.

CVE-2026-34786 - remediation guidance & executive summary

Description

Rack is a modular Ruby web server interface. Prior to versions 2.2.23, 3.1.21, and 3.2.6, Rack::Static#applicable_rules evaluates several header_rules types against the raw URL-encoded PATH_INFO, while the underlying file-serving path is decoded before the file is served. As a result, a request for a URL-encoded variant of a static path can serve the same file without the headers that header_rules were intended to apply. In deployments that rely on Rack::Static to attach security-relevant response headers to static content, this can allow an attacker to bypass those headers by requesting an encoded form of the path. This issue has been patched in versions 2.2.23, 3.1.21, and 3.2.6.

CVSS Metrics

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
Attack Vector: network
Complexity: low
Privileges: none
User Action: none
Scope: unchanged
Confidentiality: none
Integrity: low
Availability: none
Weaknesses: CWE-180

Metadata

Primary Vendor: RACK
Published: 4/2/2026
Last Modified: 4/16/2026
Source: NIST NVD
Note: Verify all details with official vendor sources before applying patches.

Affected Products

rack : rackrack : rackrack : rack

Remediation Guidance

Executive Summary

Cite this page

CVE-2026-34786. CVEDatabase.com. Retrieved 1 May 2026. https://cvedatabase.com/cve/CVE-2026-34786

View on NIST NVD

CVE-2026-34786 vulnerability