CVE-2026-72721

{"id": "CVE-2026-72721", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-72721", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "yes"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2026-08-10T16:58:55.983146Z"}}], "cvssMetricV31": [{"type": "Secondary", "source": "security-advisories@github.com", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 5.3, "attackVector": "NETWORK", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "NONE", "confidentialityImpact": "LOW"}, "impactScore": 1.4, "exploitabilityScore": 3.9}]}, "affected": [{"source": "security-advisories@github.com", "affectedData": [{"vendor": "discourse", "product": "discourse", "versions": [{"status": "affected", "version": "< 2026.1.6"}, {"status": "affected", "version": ">= 2026.5.0-latest, < 2026.5.2"}, {"status": "affected", "version": ">= 2026.6.0-latest, < 2026.6.1"}, {"status": "affected", "version": ">= 2026.7.0-latest, < 2026.7.0"}]}]}], "published": "2026-08-10T16:19:49.360", "references": [{"url": "https://github.com/discourse/discourse/commit/a3e10759fef47f03d450649bb51d9e84f4c68b8f", "source": "security-advisories@github.com"}, {"url": "https://github.com/discourse/discourse/commit/c2eb6b0e5597d6f28f4be739b83300bc9c69e3cd", "source": "security-advisories@github.com"}, {"url": "https://github.com/discourse/discourse/commit/caa615c371b1696982ee11ac8f3558f0f8ced584", "source": "security-advisories@github.com"}, {"url": "https://github.com/discourse/discourse/commit/f503971d311b7b0dfdb751ee8cfd67e8cb99f5c5", "source": "security-advisories@github.com"}, {"url": "https://github.com/discourse/discourse/pull/42091", "source": "security-advisories@github.com"}, {"url": "https://github.com/discourse/discourse/pull/42092", "source": "security-advisories@github.com"}, {"url": "https://github.com/discourse/discourse/pull/42093", "source": "security-advisories@github.com"}, {"url": "https://github.com/discourse/discourse/pull/42094", "source": "security-advisories@github.com"}, {"url": "https://github.com/discourse/discourse/security/advisories/GHSA-3x7x-24rq-h5j6", "source": "security-advisories@github.com"}], "vulnStatus": "Deferred", "weaknesses": [{"type": "Secondary", "source": "security-advisories@github.com", "description": [{"lang": "en", "value": "CWE-178"}]}], "descriptions": [{"lang": "en", "value": "Discourse is an open-source discussion platform. Prior to 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0, Onebox::DomainChecker.is_blocked? compares hostnames and SiteSetting.blocked_onebox_domains entries case-sensitively, allowing an attacker to bypass configured Onebox domain restrictions by changing character casing in a redirect target hostname. This issue is fixed in versions 2026.1.6, 2026.5.2, 2026.6.1, and 2026.7.0."}], "lastModified": "2026-09-08T20:54:37.790", "sourceIdentifier": "security-advisories@github.com"}