{"id":"CVE-2026-77804","revision":null,"records":[{"revision":"3abbe0b647d14b50ba18e0a9dc5677d0","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-77804","aliases":[],"title":"Time-of-check Time-of-use (TOCTOU) Race Condition in Root Certificate Installation in Progress® Telerik® Fiddler® Classic","description":"In Progress® Telerik® Fiddler® Classic for Windows, versions prior to v6.0.20262.10021, a time-of-check time-of-use (TOCTOU) race condition exists in the installation of the HTTPS interception root certificate into the Local Computer certificate store. Fiddler writes the certificate to a temporary file in a user-writable location and then launches the external TrustCert helper application, which elevates and imports the certificate from that file. A local threat actor with low privileges who replaces the temporary file between the time it is written and the time the elevated helper reads it can cause an attacker-supplied root certificate to be installed in the Local Computer Trusted Root Certification Authorities store, enabling subsequent interception and modification of TLS-protected traffic on the machine. Successful exploitation requires the user to initiate the certificate trust operation and approve the elevation prompt.","state":0,"publishedAt":"2026-10-05T12:40:26.811+00:00","modifiedAt":"2026-10-06T17:49:23.338+00:00","affected":[{"ecosystem":"Vendor product","name":"Progress® Telerik® Fiddler® Classic","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"Progress Software\",\n                    \"product\": \"Progress® Telerik® Fiddler® Classic\",\n                    \"platforms\": [\n                        \"Windows\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"status\": \"affected\",\n                            \"version\": \"1.0.0\",\n                            \"lessThan\": \"6.0.20262.10021\",\n                            \"versionType\": \"custom\"\n                        }\n                    ],\n                    \"defaultStatus\": \"unaffected\"\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N","score":6.6,"severity":"MEDIUM"}],"references":["https://docs.telerik.com/fiddler/knowledge-base/kb-security-root-certificate-installation-toctou-cve-2026-77804"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-77804","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-77804","identifiers":["CVE-2026-77804"]},"retained":false,"historicalAffected":[]}],"coverage":[{"source":"cisa-kev:global","scope":"Complete CISA KEV catalog; all vendors. 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Not a global EUVD catalog. Successful not-found lookups count as checked; they do not imply withdrawal or safety. No reader inventory is sent.","generation":"enrichment-f0a4583a21084daab8e852bf5d038b99","complete":false,"records":13759,"lastAttemptAt":"2026-11-11T14:09:33.1310684+00:00","lastSuccessAt":"2026-11-11T14:09:33.127+00:00","error":null,"lastVerifiedAt":"2026-11-11T14:09:33.127+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":13569,"expectedIdentifiers":13813,"failedIdentifiers":0},{"source":"first-epss:nuget","scope":"FIRST EPSS for explicit CVE aliases in the collected public NuGet archive. Not a global EPSS backfill.","generation":"2026-11-11T13:57:33.6529555+00:00","complete":true,"records":1097,"lastAttemptAt":"2026-11-11T13:57:33.6529555+00:00","lastSuccessAt":"2026-11-11T13:57:33.8250558+00:00","error":null,"lastVerifiedAt":"2026-11-11T13:57:33.8250561+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"nvd","scope":"Rolling NVD lookups of CVE aliases in current public OSV archives; 500 identifiers per refresh, rechecked after 48 hours. Not a global NVD catalog. Successful not-found lookups count as checked; they do not imply withdrawal or safety. No reader inventory is sent.","generation":"enrichment-11785b13898646a1917b06b09d2df4a4","complete":true,"records":13753,"lastAttemptAt":"2026-11-11T13:57:34.9144807+00:00","lastSuccessAt":"2026-11-11T13:57:34.909+00:00","error":null,"lastVerifiedAt":"2026-11-11T13:57:34.909+00:00","snapshotPublishedAt":null,"importing":false,"stagedRecords":0,"checkedIdentifiers":13813,"expectedIdentifiers":13813,"failedIdentifiers":0},{"source":"osv:Go","scope":"Complete OSV Go ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"go-3562b6c78fd1bd0f0b55daf66a0926ae24f65e462df7f6d928caad458fc696bf","complete":true,"records":9947,"lastAttemptAt":"2026-11-11T13:57:33.3950468+00:00","lastSuccessAt":"2026-11-11T04:27:43.6877707+00:00","error":null,"lastVerifiedAt":"2026-11-11T13:57:33.3950468+00:00","snapshotPublishedAt":"2026-11-11T03:32:46+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:NuGet","scope":"Complete OSV NuGet ecosystem archive, including GitHub Advisory Database records; NuGet version matching only","generation":"nuget-456002455e0ab94bb92c95476d4e6d175c104cd594749982afd96c893728ecbc","complete":true,"records":2010,"lastAttemptAt":"2026-11-11T13:57:32.9057946+00:00","lastSuccessAt":"2026-11-11T02:36:58.1276999+00:00","error":null,"lastVerifiedAt":"2026-11-11T13:57:32.9057946+00:00","snapshotPublishedAt":"2026-11-11T01:17:51+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:crates.io","scope":"Complete OSV crates.io ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"crates.io-baa8362b4daf9e5f39d5563775a55935e7b442c0735d33274a921579ce4a0d66","complete":true,"records":3093,"lastAttemptAt":"2026-11-11T13:57:33.6132068+00:00","lastSuccessAt":"2026-11-11T13:00:02.5446881+00:00","error":null,"lastVerifiedAt":"2026-11-11T13:57:33.6132068+00:00","snapshotPublishedAt":"2026-11-11T12:47:47+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null},{"source":"osv:npm","scope":"Complete OSV npm ecosystem archive, including withdrawn and malicious-package source records; statement counts are not unique CVE counts","generation":"npm-10cb353ca77c2a8069d6892d1d394d936b12c0add3c8749e2a1a03a1c5d50426","complete":true,"records":231666,"lastAttemptAt":"2026-11-11T13:57:33.0989698+00:00","lastSuccessAt":"2026-11-11T12:59:55.8981437+00:00","error":null,"lastVerifiedAt":"2026-11-11T13:57:33.0989698+00:00","snapshotPublishedAt":"2026-11-11T12:32:53+00:00","importing":false,"stagedRecords":0,"checkedIdentifiers":null,"expectedIdentifiers":null,"failedIdentifiers":null}]}