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Medium

SvelteKit before 3.0.0 XSS via Cache-Control Header in Prerendered Pages

Type: advisorySources: Official CVE List

SvelteKit (@sveltejs/kit) before 3.0.0 contains a cross-site scripting vulnerability in prerendered pages because a cache-control header value set via setHeaders is inserted without escaping into a tag. An attacker who can influence that untrusted value at prerender time can break out of the content attribute and inject HTML or JavaScript that executes when users visit the page.

Products
kit
Affected versions
Not specified
Fixed versions
Not specified
CVEs
CVE-2026-114061
Confirmed fixed CVEs
Not specified
Updated in this feed
1 Nov 2026, 15:56 UTC · Revision 2

Source evidence

SvelteKit before 3.0.0 XSS via Cache-Control Header in Prerendered Pages

core-cve · Original source

Published 21 Oct 2026, 00:36 UTC

SvelteKit (@sveltejs/kit) before 3.0.0 contains a cross-site scripting vulnerability in prerendered pages because a cache-control header value set via setHeaders is inserted without escaping into a tag. An attacker who can influence that untrusted value at prerender time can break out of the content attribute and inject HTML or JavaScript that executes when users visit the page.

cve:CVE-2026-114061

kit

Fixed versions: Not specified

Complete source record
{
  "id": "3c14cc0ccd17758ae0d67439adfe2126d4ee444cf3f0743407f7555ba3fd2773",
  "url": "https://www.cve.org/CVERecord?id=CVE-2026-114061",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "SvelteKit before 3.0.0 XSS via Cache-Control Header in Prerendered Pages",
    "summary": "SvelteKit (@sveltejs/kit) before 3.0.0 contains a cross-site scripting vulnerability in prerendered pages because a cache-control header value set via setHeaders is inserted without escaping into a tag. An attacker who can influence that untrusted value at prerender time can break out of the content attribute and inject HTML or JavaScript that executes when users visit the page.",
    "evidence": "cve:CVE-2026-114061",
    "products": [
      {
        "name": {
          "value": "kit",
          "evidence": "/containers/cna/affected/0/product"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": []
      }
    ],
    "severity": "medium",
    "structured": {
      "id": "CVE-2026-114061",
      "aliases": [
        "CVE-2026-114061"
      ],
      "metrics": [
        {
          "format": "CVSS",
          "cvssV4_0": {
            "version": "4.0",
            "baseScore": 2.3,
            "attackVector": "NETWORK",
            "baseSeverity": "LOW",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N",
            "userInteraction": "PASSIVE",
            "attackComplexity": "LOW",
            "attackRequirements": "PRESENT",
            "privilegesRequired": "NONE",
            "subIntegrityImpact": "LOW",
            "vulnIntegrityImpact": "NONE",
            "subAvailabilityImpact": "NONE",
            "vulnAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "LOW",
            "vulnConfidentialityImpact": "NONE"
          }
        },
        {
          "format": "CVSS",
          "cvssV3_1": {
            "scope": "CHANGED",
            "version": "3.1",
            "baseScore": 4.7,
            "attackVector": "NETWORK",
            "baseSeverity": "MEDIUM",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N",
            "integrityImpact": "LOW",
            "userInteraction": "REQUIRED",
            "attackComplexity": "HIGH",
            "availabilityImpact": "NONE",
            "privilegesRequired": "NONE",
            "confidentialityImpact": "LOW"
          }
        }
      ],
      "affected": [
        {
          "vendor": "sveltejs",
          "product": "kit",
          "versions": [
            {
              "status": "affected",
              "version": "0",
              "lessThan": "3.0.0",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "3.0.0",
              "versionType": "semver"
            }
          ],
          "packageURL": "pkg:npm/%40sveltejs/kit",
          "defaultStatus": "unaffected"
        }
      ],
      "modified": "2026-10-28T15:19:51.281Z",
      "provider": "cve",
      "references": [
        "https://github.com/sveltejs/kit/security/advisories/GHSA-27mw-82g8-phjj",
        "https://www.vulncheck.com/advisories/sveltekit-before-3.0.0-xss-via-cache-control-header-in-prerendered-pages"
      ],
      "provider_metadata": {
        "adp": [
          {
            "title": "CISA ADP Vulnrichment",
            "metrics": [
              {
                "other": {
                  "type": "ssvc",
                  "content": {
                    "id": "CVE-2026-114061",
                    "role": "CISA Coordinator",
                    "options": [
                      {
                        "Exploitation": "none"
                      },
                      {
                        "Automatable": "no"
                      },
                      {
                        "Technical Impact": "partial"
                      }
                    ],
                    "version": "2.0.3",
                    "timestamp": "2026-10-28T15:19:38.675963Z"
                  }
                }
              }
            ],
            "providerMetadata": {
              "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
              "shortName": "CISA-ADP",
              "dateUpdated": "2026-10-28T15:19:51.281Z"
            }
          }
        ],
        "cna": {
          "orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
          "shortName": "VulnCheck",
          "dateUpdated": "2026-10-21T00:36:35.456Z"
        }
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-114061",
        "evidence": "/cveMetadata/cveId"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/containers/cna/metrics"
  },
  "source_id": "core-cve",
  "document_id": 456113,
  "published_at": "2026-10-21T00:36:35.456+00:00"
}