{"id":"CVE-2026-27122","aliases":["CLSA-2026-1775953999","CLSA-2026-1776040402","CLSA-2026-1776126838","CLSA-2026-1776213244","CLSA-2026-1776213252","EUVD-2026-7538","GHSA-m56q-vw4c-c2cp"],"status":"published","title":"Svelte SSR does not validate dynamic element tag names in `\u003csvelte:element\u003e`","description":"svelte performance oriented web framework. Prior to 5.51.5, when using \u003csvelte:element this={tag}\u003e in server-side rendering, the provided tag name is not validated or sanitized before being emitted into the HTML output. If the tag string contains unexpected characters, it can result in HTML injection in the SSR output. Client-side rendering is not affected. This vulnerability is fixed in 5.51.5.","severity":{"version":"4.0","score":5.1,"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","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.0022,"percentile":0.12681,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-79"],"published":"2026-02-19T15:18:42Z","modified":"2026-10-28T02:30:38Z","fixes":[{"ecosystem":"npm","package":"svelte","fixed_in":["5.51.5"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"npm","package":"svelte","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"5.51.4"},{"fixed":"5.51.5"}]}]},{"source":"osv","ecosystem":"TuxCare:npm","package":"svelte","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.2.20-tuxcare.0"},{"fixed":"4.2.20-tuxcare.1"}]}],"versions":["4.2.20"],"bundled":4},{"source":"osv","ecosystem":"TuxCare:npm","package":"svelte","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"3.59.2-tuxcare.0"},{"fixed":"3.59.2-tuxcare.1"}]}],"versions":["3.59.2"],"bundled":5},{"source":"osv","ecosystem":"TuxCare:npm","package":"svelte","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"2.16.1-tuxcare.0"},{"fixed":"2.16.1-tuxcare.1"}]}],"versions":["2.16.1"],"bundled":6},{"source":"osv","ecosystem":"TuxCare:npm","package":"svelte","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"1.64.1-tuxcare.0"},{"fixed":"1.64.1-tuxcare.1"}]}],"versions":["1.64.1"],"bundled":6},{"source":"osv","ecosystem":"TuxCare:npm","package":"svelte","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0.3.0-tuxcare.0"},{"fixed":"0.3.0-tuxcare.1"}]}],"versions":["0.3.0"],"bundled":6},{"source":"osv","ecosystem":"npm","package":"svelte","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"5.51.5"}]}]}],"products":[{"vendor":"svelte","product":"svelte"},{"vendor":"sveltejs","product":"svelte"}],"references":[{"url":"https://github.com/sveltejs/svelte/security/advisories/GHSA-m56q-vw4c-c2cp","tags":["x_refsource_CONFIRM","Vendor Advisory","advisory","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-27122","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-m56q-vw4c-c2cp"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/27xxx/CVE-2026-27122.json","tags":["advisory"]},{"url":"https://github.com/sveltejs/svelte","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-27122","title":"Svelte SSR does not validate dynamic element tag names in `\u003csvelte:element\u003e`","description":"svelte performance oriented web framework. Prior to 5.51.5, when using \u003csvelte:element this={tag}\u003e in server-side rendering, the provided tag name is not validated or sanitized before being emitted into the HTML output. If the tag string contains unexpected characters, it can result in HTML injection in the SSR output. Client-side rendering is not affected. This vulnerability is fixed in 5.51.5.","status":"published","published":"2026-02-20T22:28:37.824Z","modified":"2026-02-23T19:23:03.403Z","cvss":[{"version":"4.0","score":5.1,"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","level":"medium","assessor":"cna"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T14:19:49.199185Z"}],"euvd":[{"id":"EUVD-2026-7538","description":"svelte performance oriented web framework. Prior to 5.51.5, when using \u003csvelte:element this={tag}\u003e in server-side rendering, the provided tag name is not validated or sanitized before being emitted into the HTML output. If the tag string contains unexpected characters, it can result in HTML injection in the SSR output. Client-side rendering is not affected. This vulnerability is fixed in 5.51.5.","status":"published","published":"2026-02-20T22:28:37Z","modified":"2026-02-23T19:23:03Z","cvss":[{"version":"4.0","score":5.1,"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","level":"medium"}],"updated_at":"2026-11-02T19:48:32.158773Z"}],"ghsa":[{"id":"GHSA-m56q-vw4c-c2cp","title":"Svelte SSR does not validate dynamic element tag names in `\u003csvelte:element\u003e`","description":"When using `\u003csvelte:element this={tag}\u003e` in server-side rendering, the provided tag name is not validated or sanitized before being emitted into the HTML output. If the tag string contains unexpected characters, it can result in HTML injection in the SSR output. Client-side rendering is not affected.","status":"published","published":"2026-02-19T15:18:42Z","modified":"2026-02-23T22:23:26Z","cvss":[{"version":"4.0","score":5.1,"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","level":"medium"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T14:39:26.881079Z"}],"nvd":[{"id":"CVE-2026-27122","description":"svelte performance oriented web framework. Prior to 5.51.5, when using \u003csvelte:element this={tag}\u003e in server-side rendering, the provided tag name is not validated or sanitized before being emitted into the HTML output. If the tag string contains unexpected characters, it can result in HTML injection in the SSR output. Client-side rendering is not affected. This vulnerability is fixed in 5.51.5.","status":"published","published":"2026-02-20T23:16:02.64Z","modified":"2026-06-17T10:26:42.403Z","cvss":[{"version":"4.0","score":5.1,"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"medium","assessor":"secondary"},{"version":"3.1","score":5.4,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N","level":"medium","assessor":"primary"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T14:12:06.63895Z"}],"osv":[{"id":"CVE-2026-27122","title":"Svelte SSR does not validate dynamic element tag names in `\u003csvelte:element\u003e`","description":"svelte performance oriented web framework. Prior to 5.51.5, when using \u003csvelte:element this={tag}\u003e in server-side rendering, the provided tag name is not validated or sanitized before being emitted into the HTML output. If the tag string contains unexpected characters, it can result in HTML injection in the SSR output. Client-side rendering is not affected. This vulnerability is fixed in 5.51.5.","status":"published","published":"2026-02-20T22:28:37.824Z","modified":"2026-10-28T02:30:38.371487292Z","cvss":[{"version":"4.0","score":5.1,"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","level":"medium"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T15:44:59.80315Z"},{"id":"GHSA-m56q-vw4c-c2cp","title":"Svelte SSR does not validate dynamic element tag names in `\u003csvelte:element\u003e`","description":"When using `\u003csvelte:element this={tag}\u003e` in server-side rendering, the provided tag name is not validated or sanitized before being emitted into the HTML output. If the tag string contains unexpected characters, it can result in HTML injection in the SSR output. Client-side rendering is not affected.","status":"published","published":"2026-02-19T15:18:42Z","modified":"2026-09-10T03:50:35.273929194Z","cvss":[{"version":"4.0","score":5.1,"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","level":"medium"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T15:46:51.463834Z"},{"id":"CLSA-2026-1775953999","title":"TuxCare security update for svelte (4 CVEs)","description":"TuxCare rebuilt svelte to address 4 CVEs. Fixed in 4.2.20-tuxcare.1.","status":"published","published":"2026-08-04T14:52:24Z","modified":"2026-10-15T09:46:36.148671239Z","updated_at":"2026-11-02T15:43:44.009773Z"},{"id":"CLSA-2026-1776040402","title":"TuxCare security update for svelte (5 CVEs)","description":"TuxCare rebuilt svelte to address 5 CVEs. Fixed in 3.59.2-tuxcare.1.","status":"published","published":"2026-08-04T14:52:24Z","modified":"2026-10-15T09:46:35.699918221Z","updated_at":"2026-11-02T15:43:44.009773Z"},{"id":"CLSA-2026-1776126838","title":"TuxCare security update for svelte (6 CVEs)","description":"TuxCare rebuilt svelte to address 6 CVEs. Fixed in 2.16.1-tuxcare.1.","status":"published","published":"2026-08-04T14:52:25Z","modified":"2026-10-15T09:47:49.780187973Z","updated_at":"2026-11-02T15:43:44.009773Z"},{"id":"CLSA-2026-1776213244","title":"TuxCare security update for svelte (6 CVEs)","description":"TuxCare rebuilt svelte to address 6 CVEs. Fixed in 1.64.1-tuxcare.1.","status":"published","published":"2026-08-04T14:52:25Z","modified":"2026-10-15T09:47:49.789990366Z","updated_at":"2026-11-02T15:43:44.009773Z"},{"id":"CLSA-2026-1776213252","title":"TuxCare security update for svelte (6 CVEs)","description":"TuxCare rebuilt svelte to address 6 CVEs. Fixed in 0.3.0-tuxcare.1.","status":"published","published":"2026-08-04T14:52:25Z","modified":"2026-10-15T09:47:49.842946726Z","updated_at":"2026-11-02T15:43:44.009773Z"}]}}