{"id":"CVE-2026-27121","state":"PUBLISHED","title":"Svelte affected by cross-site scripting via spread attributes in Svelte SSR","description":"svelte performance oriented web framework. Versions of svelte prior to 5.51.5 are vulnerable to cross-site scripting (XSS) during server-side rendering. When using spread syntax to render attributes from untrusted data, event handler properties are included in the rendered HTML output. If an application spreads user-controlled or external data as element attributes, an attacker can inject malicious event handlers that execute in victims' browsers. This vulnerability is fixed in 5.51.5.","publishedAt":"2026-02-20T22:27:36.103Z","updatedAt":"2026-02-23T19:34:18.150Z","severity":{"score":5.1,"label":"Medium","version":"4.0","vector":"CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:N/VC:L/VI:N/VA:N/SC:H/SI:H/SA:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["sveltejs svelte"],"affected":[{"vendor":"sveltejs","product":"svelte","versions":[{"version":"< 5.51.5","status":"affected"}]}],"references":["https://github.com/sveltejs/svelte/security/advisories/GHSA-f7gr-6p89-r883"],"weaknesses":["CWE-79"],"ingestedAt":"2026-10-29T20:11:31.369Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/27xxx/CVE-2026-27121.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-27121","state":"PUBLISHED","datePublished":"2026-02-20T22:27:36.103Z","dateUpdated":"2026-02-23T19:34:18.150Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-02-17T18:42:27.043Z"},"containers":{"cna":{"title":"Svelte affected by cross-site scripting via spread attributes in Svelte SSR","descriptions":[{"lang":"en","value":"svelte performance oriented web framework. Versions of svelte prior to 5.51.5 are vulnerable to cross-site scripting (XSS) during server-side rendering. When using spread syntax to render attributes from untrusted data, event handler properties are included in the rendered HTML output. If an application spreads user-controlled or external data as element attributes, an attacker can inject malicious event handlers that execute in victims' browsers. This vulnerability is fixed in 5.51.5."}],"affected":[{"vendor":"sveltejs","product":"svelte","versions":[{"version":"< 5.51.5","status":"affected"}]}],"references":[{"url":"https://github.com/sveltejs/svelte/security/advisories/GHSA-f7gr-6p89-r883","name":"https://github.com/sveltejs/svelte/security/advisories/GHSA-f7gr-6p89-r883","tags":["x_refsource_CONFIRM"]}],"metrics":[{"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"HIGH","attackRequirements":"PRESENT","privilegesRequired":"HIGH","userInteraction":"NONE","vulnConfidentialityImpact":"LOW","vulnIntegrityImpact":"NONE","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"HIGH","subIntegrityImpact":"HIGH","subAvailabilityImpact":"NONE","baseScore":5.1,"baseSeverity":"MEDIUM","vectorString":"CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:N/VC:L/VI:N/VA:N/SC:H/SI:H/SA:N","version":"4.0"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-79","lang":"en","description":"CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-02-20T22:27:36.103Z"},"source":{"advisory":"GHSA-f7gr-6p89-r883","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-02-23T19:31:36.117864Z","id":"CVE-2026-27121","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":"2026-02-23T19:34:18.150Z"}}]}}}