CVE-2026-86251

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{"bugzilla": {"description": "h3: h3: Information disclosure via path traversal due to double-decoding flaw", "id": "2529161", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2529161"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.9", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N", "status": "draft"}, "cwe": "CWE-22", "details": ["h3 versions before 1.15.9 contain a path traversal vulnerability in the serveStatic utility. A double-decoding flaw allows a request path containing double-encoded dot sequences (e.g. %252e%252e) to be decoded to %2e%2e, which survives resolveDotSegments() because that function only checks for literal '.' characters. When the resulting asset ID is resolved by URL-based backends (CDN, S3, object storage), %2e%2e is interpreted as '..' per RFC 3986, enabling path traversal to read arbitrary files from the backend.", "A flaw was found in h3. A remote attacker could exploit a path traversal vulnerability in the serveStatic utility. This vulnerability arises from a double-decoding flaw, where specially crafted, double-encoded dot sequences in a request path are incorrectly processed. This allows an attacker to bypass security checks and read arbitrary files from backend storage systems, leading to information disclosure."], "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-2026-86251", "package_state": [{"cpe": "cpe:/a:redhat:openshift_ai", "fix_state": "Fix deferred", "package_name": "rhoai/odh-feature-server-rhel9", "product_name": "Red Hat OpenShift AI (RHOAI)"}], "public_date": "2026-09-06T12:00:26Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-86251\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-86251\nhttps://github.com/h3js/h3/security/advisories/GHSA-72gr-qfp7-vwhw\nhttps://www.vulncheck.com/advisories/h3-before-1.15.9-path-traversal-via-double-decoding"], "statement": "Moderate: A path traversal vulnerability exists in the `serveStatic` utility of `h3` due to a double-decoding flaw. This issue allows an attacker to bypass path sanitization by using specially crafted double-encoded dot sequences, potentially leading to information disclosure from URL-based backends. The complexity of crafting such an attack contributes to its Moderate impact, as it requires specific input manipulation to exploit.", "threat_severity": "Moderate"}

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