CVE-2026-34786

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{"bugzilla": {"description": "rack: Rack: Security header bypass via URL-encoded static path requests", "id": "2454507", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2454507"}, "csaw": false, "cvss3": {"cvss3_base_score": "6.5", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N", "status": "draft"}, "cwe": "CWE-179", "details": ["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.", "A flaw was found in Rack. A remote attacker can exploit this vulnerability by sending a specially crafted request with a URL-encoded static path. This bypasses security-relevant response headers intended for static content, potentially leading to information disclosure or other unintended consequences."], "mitigation": {"lang": "en:us", "value": "Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability."}, "name": "CVE-2026-34786", "package_state": [{"cpe": "cpe:/a:redhat:logging:5", "fix_state": "Fix deferred", "package_name": "openshift-logging/cluster-logging-operator-bundle", "product_name": "Logging Subsystem for Red Hat OpenShift"}, {"cpe": "cpe:/a:redhat:logging:5", "fix_state": "Fix deferred", "package_name": "openshift-logging/cluster-logging-rhel9-operator", "product_name": "Logging Subsystem for Red Hat OpenShift"}, {"cpe": "cpe:/a:redhat:logging:5", "fix_state": "Fix deferred", "package_name": "openshift-logging/eventrouter-rhel9", "product_name": "Logging Subsystem for Red Hat OpenShift"}, {"cpe": "cpe:/a:redhat:logging:5", "fix_state": "Fix deferred", "package_name": "openshift-logging/fluentd-rhel9", "product_name": "Logging Subsystem for Red Hat OpenShift"}, {"cpe": "cpe:/a:redhat:logging:5", "fix_state": "Fix deferred", "package_name": "openshift-logging/log-file-metric-exporter-rhel9", "product_name": "Logging Subsystem for Red Hat OpenShift"}, {"cpe": "cpe:/a:redhat:logging:5", "fix_state": "Fix deferred", "package_name": "openshift-logging/logging-view-plugin-rhel9", "product_name": "Logging Subsystem for Red Hat OpenShift"}, {"cpe": "cpe:/a:redhat:logging:5", "fix_state": "Fix deferred", "package_name": "openshift-logging/vector-rhel9", "product_name": "Logging Subsystem for Red Hat OpenShift"}, {"cpe": "cpe:/a:redhat:red_hat_3scale_amp:2", "fix_state": "Fix deferred", "package_name": "3scale-amp20/backend", "product_name": "Red Hat 3scale API Management Platform 2"}, {"cpe": "cpe:/a:redhat:red_hat_3scale_amp:2", "fix_state": "Fix deferred", "package_name": "3scale-amp20/system", "product_name": "Red Hat 3scale API Management Platform 2"}, {"cpe": "cpe:/a:redhat:red_hat_3scale_amp:2", "fix_state": "Fix deferred", "package_name": "3scale-amp21/backend", "product_name": "Red Hat 3scale API Management Platform 2"}, {"cpe": "cpe:/a:redhat:red_hat_3scale_amp:2", "fix_state": "Fix deferred", "package_name": "3scale-amp21/system", "product_name": "Red Hat 3scale API Management Platform 2"}, {"cpe": "cpe:/a:redhat:red_hat_3scale_amp:2", "fix_state": "Fix deferred", "package_name": "3scale-amp21/zync", "product_name": "Red Hat 3scale API Management Platform 2"}, {"cpe": "cpe:/a:redhat:red_hat_3scale_amp:2", "fix_state": "Fix deferred", "package_name": "3scale-amp22/backend", "product_name": "Red Hat 3scale API Management Platform 2"}, {"cpe": "cpe:/a:redhat:red_hat_3scale_amp:2", "fix_state": "Fix deferred", "package_name": "3scale-amp22/system", "product_name": "Red Hat 3scale API Management Platform 2"}, {"cpe": "cpe:/a:redhat:red_hat_3scale_amp:2", "fix_state": "Fix deferred", "package_name": "3scale-amp22/zync", "product_name": "Red Hat 3scale API Management Platform 2"}, {"cpe": "cpe:/a:redhat:red_hat_3scale_amp:2", "fix_state": "Fix deferred", "package_name": "3scale-amp24/backend", "product_name": "Red Hat 3scale API Management Platform 2"}, {"cpe": "cpe:/a:redhat:red_hat_3scale_amp:2", "fix_state": "Fix deferred", "package_name": "3scale-amp24/system", "product_name": "Red Hat 3scale API Management Platform 2"}, {"cpe": "cpe:/a:redhat:red_hat_3scale_amp:2", "fix_state": "Fix deferred", "package_name": "3scale-amp24/zync", "product_name": "Red Hat 3scale API Management Platform 2"}, {"cpe": "cpe:/a:redhat:red_hat_3scale_amp:2", "fix_state": "Fix deferred", "package_name": "3scale-amp25/backend", "product_name": "Red Hat 3scale API Management Platform 2"}, {"cpe": "cpe:/a:redhat:red_hat_3scale_amp:2", "fix_state": "Fix deferred", 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"3scale-amp2/zync-rhel8", "product_name": "Red Hat 3scale API Management Platform 2"}, {"cpe": "cpe:/a:redhat:red_hat_3scale_amp:2", "fix_state": "Fix deferred", "package_name": "3scale-amp2/zync-rhel9", "product_name": "Red Hat 3scale API Management Platform 2"}, {"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Fix deferred", "package_name": "pcs", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Fix deferred", "package_name": "pcs", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Fix deferred", "package_name": "pcs", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "pcs", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "rhel9/ruby-30", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "rhel9/ruby-33", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "ubi9/ruby-30", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "ubi9/ruby-33", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-04-02T16:44:59Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-34786\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-34786\nhttps://github.com/rack/rack/security/advisories/GHSA-q4qf-9j86-f5mh"], "threat_severity": "Moderate"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[0,2.2.23)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "[3.0.0.beta1,3.1.21)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[3.2.0,3.2.6)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "rack", "source": "cna", "vendor": "rack"}, "product": "rack", "vendor": "rack"}], "analysis": {"en": {"generated_at": "2026-04-04T03:57:28.216625+00:00", "value": {"mitigation_remediation": ["Upgrade Rack to version 2.2.23, 3.1.21, or 3.2.6 or later", "If upgrading is not immediately possible, remove or reconfigure Rack::Static header_rules for static resources or replace with a dedicated static file handler that sets appropriate headers", "Verify that all static content served includes necessary security headers such as X-Content-Type-Options and X-Frame-Options"], "summary": {"action": "Immediate patch", "impact": "Security header bypass"}, "threat_synthesis": {"affected_systems": "The vulnerability affects installations of Rack using any version earlier than 2.2.23, 3.1.21, or 3.2.6. Deployments that rely on Rack::Static to add security headers to static content are impacted.", "description_and_impact": "Rack::Static evaluated header_rules against the raw URL\u2011encoded PATH_INFO while serving the file from the decoded path. This mismatch allows a request for an encoded variant of a static resource to bypass the security\u2011relevant headers that the header_rules are meant to apply, potentially exposing the server to attacks that rely on those headers such as click\u2011jacking or MIME\u2011type sniffing. The flaw is a form of code path error that could undermine the intended integrity controls on static content.", "risk_and_exploitability": "The CVSS score of 5.3 indicates moderate severity, and the EPSS score of less than 1% suggests a low likelihood of widespread exploitation. The vulnerability is not listed in CISA\u2019s KEV catalog. An attacker can exploit it by crafting an external HTTP request with an URL\u2011encoded path to a static file; the request is processed against the encoded path for header matching but the decoded path is served without the intended headers. No payload is required beyond normal URL encoding."}}}}, "created": "2026-04-03T07:32:34.842456+00:00", "updated": "2026-04-07T07:55:57.253666+00:00", "vendors": ["rack", "rack$PRODUCT$rack"]}