{"id":"CVE-2026-27125","state":"PUBLISHED","title":"Svelte SSR attribute spreading includes inherited properties from prototype chain","description":"svelte performance oriented web framework. Prior to 5.51.5, in server-side rendering, attribute spreading on elements (e.g. <div {...attrs}>) enumerates inherited properties from the object's prototype chain rather than only own properties. In environments where Object.prototype has already been polluted — a precondition outside of Svelte's control — this can cause unexpected attributes to appear in SSR output or cause SSR to throw errors. Client-side rendering is not affected. This vulnerability is fixed in 5.51.5.","publishedAt":"2026-02-20T22:29:45.364Z","updatedAt":"2026-02-25T21:33:14.822Z","severity":{"score":5.3,"label":"Medium","version":"4.0","vector":"CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:L/VI:L/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-crpf-4hrx-3jrp","https://github.com/sveltejs/svelte/commit/73098bb26c6f06e7fd1b0746d817d2c5ee90755f","https://github.com/sveltejs/svelte/releases/tag/svelte@5.51.5"],"weaknesses":["CWE-915"],"ingestedAt":"2026-10-29T20:11:31.369Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/27xxx/CVE-2026-27125.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-27125","state":"PUBLISHED","datePublished":"2026-02-20T22:29:45.364Z","dateUpdated":"2026-02-25T21:33:14.822Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-02-17T18:42:27.043Z"},"containers":{"cna":{"title":"Svelte SSR attribute spreading includes inherited properties from prototype chain","descriptions":[{"lang":"en","value":"svelte performance oriented web framework. Prior to 5.51.5, in server-side rendering, attribute spreading on elements (e.g. <div {...attrs}>) enumerates inherited properties from the object's prototype chain rather than only own properties. In environments where Object.prototype has already been polluted — a precondition outside of Svelte's control — this can cause unexpected attributes to appear in SSR output or cause SSR to throw errors. Client-side rendering is not affected. 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-crpf-4hrx-3jrp","name":"https://github.com/sveltejs/svelte/security/advisories/GHSA-crpf-4hrx-3jrp","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/sveltejs/svelte/commit/73098bb26c6f06e7fd1b0746d817d2c5ee90755f","name":"https://github.com/sveltejs/svelte/commit/73098bb26c6f06e7fd1b0746d817d2c5ee90755f","tags":["x_refsource_MISC"]},{"url":"https://github.com/sveltejs/svelte/releases/tag/svelte@5.51.5","name":"https://github.com/sveltejs/svelte/releases/tag/svelte@5.51.5","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"HIGH","attackRequirements":"PRESENT","privilegesRequired":"LOW","userInteraction":"NONE","vulnConfidentialityImpact":"LOW","vulnIntegrityImpact":"LOW","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"HIGH","subIntegrityImpact":"HIGH","subAvailabilityImpact":"NONE","baseScore":5.3,"baseSeverity":"MEDIUM","vectorString":"CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:L/VI:L/VA:N/SC:H/SI:H/SA:N","version":"4.0"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-915","lang":"en","description":"CWE-915: Improperly Controlled Modification of Dynamically-Determined Object Attributes","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-02-20T22:29:45.364Z"},"source":{"advisory":"GHSA-crpf-4hrx-3jrp","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-02-25T21:33:01.018593Z","id":"CVE-2026-27125","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":"2026-02-25T21:33:14.822Z"}}]}}}