{"id":"CVE-2026-39823","state":"PUBLISHED","title":"Bypass of meta content URL escaping causes XSS in html/template","description":"CVE-2026-27142 fixed a vulnerability in which URLs were not correctly escaped inside of a <meta> tag's <content> attribute. If the URL content were to insert ASCII whitespaces around the '=' rune inside of the <content> attribute, the escaper would fail to similarly escape it, leading to XSS.","publishedAt":"2026-05-07T19:41:19.524Z","updatedAt":"2026-05-08T14:05:55.152Z","severity":{"score":6.1,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","source":"CISA-ADP"},"assigner":"Go","products":["Go standard library html/template"],"affected":[{"vendor":"Go standard library","product":"html/template","packageName":"html/template","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThan":"1.25.10","versionType":"semver"},{"version":"1.26.0-0","status":"affected","lessThan":"1.26.3","versionType":"semver"}],"collectionURL":"https://pkg.go.dev","programRoutines":[{"name":"tMetaContent"},{"name":"Template.Execute"},{"name":"Template.ExecuteTemplate"}]}],"references":["https://go.dev/issue/78913","https://go.dev/cl/769920","https://groups.google.com/g/golang-announce/c/qcCIEXso47M","https://pkg.go.dev/vuln/GO-2026-4982"],"weaknesses":[],"ingestedAt":"2026-10-29T20:11:50.837Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/39xxx/CVE-2026-39823.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-39823","state":"PUBLISHED","datePublished":"2026-05-07T19:41:19.524Z","dateUpdated":"2026-05-08T14:05:55.152Z","assignerShortName":"Go","assignerOrgId":"1bb62c36-49e3-4200-9d77-64a1400537cc","dateReserved":"2026-04-07T18:13:03.527Z"},"containers":{"cna":{"title":"Bypass of meta content URL escaping causes XSS in html/template","descriptions":[{"lang":"en","value":"CVE-2026-27142 fixed a vulnerability in which URLs were not correctly escaped inside of a <meta> tag's <content> attribute. If the URL content were to insert ASCII whitespaces around the '=' rune inside of the <content> attribute, the escaper would fail to similarly escape it, leading to XSS."}],"affected":[{"vendor":"Go standard library","product":"html/template","packageName":"html/template","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThan":"1.25.10","versionType":"semver"},{"version":"1.26.0-0","status":"affected","lessThan":"1.26.3","versionType":"semver"}],"collectionURL":"https://pkg.go.dev","programRoutines":[{"name":"tMetaContent"},{"name":"Template.Execute"},{"name":"Template.ExecuteTemplate"}]}],"references":[{"url":"https://go.dev/issue/78913"},{"url":"https://go.dev/cl/769920"},{"url":"https://groups.google.com/g/golang-announce/c/qcCIEXso47M"},{"url":"https://pkg.go.dev/vuln/GO-2026-4982"}],"problemTypes":[{"descriptions":[{"lang":"en","description":"CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')"}]}],"providerMetadata":{"shortName":"Go","orgId":"1bb62c36-49e3-4200-9d77-64a1400537cc","dateUpdated":"2026-05-07T19:41:19.524Z"},"credits":[{"lang":"en","value":"Samy Ghannad"}]},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"cvssV3_1":{"scope":"CHANGED","version":"3.1","baseScore":6.1,"attackVector":"NETWORK","baseSeverity":"MEDIUM","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","integrityImpact":"LOW","userInteraction":"REQUIRED","attackComplexity":"LOW","availabilityImpact":"NONE","privilegesRequired":"NONE","confidentialityImpact":"LOW"}},{"other":{"type":"ssvc","content":{"timestamp":"2026-05-08T14:05:34.310805Z","id":"CVE-2026-39823","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-05-08T14:05:55.152Z"}}]}}}