CVE-2026-86205

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{"bugzilla": {"description": "h3: h3: Open Redirect vulnerability via unsanitized Referer header", "id": "2529167", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2529167"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.4", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N", "status": "draft"}, "cwe": "CWE-601", "details": ["h3 versions before 2.0.1-rc.18 contain an open redirect vulnerability in the redirectBack() utility that fails to sanitize protocol-relative paths in the Referer header pathname. Attackers can craft a same-origin URL with a double-slash path segment that passes origin validation but produces a Location header interpreted by browsers as a protocol-relative redirect to an external domain.", "A flaw was found in h3. This open redirect vulnerability exists in the `redirectBack()` utility, which fails to properly sanitize protocol-relative paths in the Referer header. A remote attacker can craft a specially designed URL that bypasses origin validation, leading to a redirect to an external, potentially malicious, domain. This could allow for phishing attacks or other malicious activities."], "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-2026-86205", "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": "2026-09-06T12:00:25Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-86205\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-86205\nhttps://github.com/h3js/h3/security/advisories/GHSA-fp4x-ggrf-wmc6\nhttps://www.vulncheck.com/advisories/h3-before-2.0.1-rc.18-open-redirect-via-redirectback"], "statement": "This Moderate severity flaw in the `h3` library, affecting Red Hat OpenShift AI, allows for an open redirect. An attacker could craft a malicious URL that, when visited by a user, redirects them to an arbitrary external domain. This vulnerability requires user interaction and could be leveraged in phishing attacks.", "threat_severity": "Moderate"}

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