Vulnerability-Lookup

GHSA-QGVG-PR8V-6RR3

Vulnerability from github – Published: 2026-02-26 22:25 – Updated: 2026-02-26 22:25

Summary

Svelte: XSS via HTML Comment Injection in SSR Error Boundary Hydration Markers

Details

Errors from transformError were not correctly escaped prior to being embedded in the HTML output, causing potential HTML injection and XSS if attacker-controlled content is returned from transformError.

Severity ?

5.3 (Medium)


                  
                    CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:L/VI:N/VA:N/SC:H/SI:H/SA:N

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{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "svelte"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "5.53.0"
            },
            {
              "fixed": "5.53.5"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-27902"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-79"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-02-26T22:25:45Z",
    "nvd_published_at": "2026-02-26T02:16:21Z",
    "severity": "MODERATE"
  },
  "details": "Errors from `transformError` were not correctly escaped prior to being embedded in the HTML output, causing potential HTML injection and XSS if attacker-controlled content is returned from `transformError`.",
  "id": "GHSA-qgvg-pr8v-6rr3",
  "modified": "2026-02-26T22:25:45Z",
  "published": "2026-02-26T22:25:45Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/sveltejs/svelte/security/advisories/GHSA-qgvg-pr8v-6rr3"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-27902"
    },
    {
      "type": "WEB",
      "url": "https://github.com/sveltejs/svelte/commit/0298e979371bb583855c9810db79a70a551d22b9"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/sveltejs/svelte"
    },
    {
      "type": "WEB",
      "url": "https://github.com/sveltejs/svelte/releases/tag/svelte@5.53.5"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:L/VI:N/VA:N/SC:H/SI:H/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Svelte: XSS via HTML Comment Injection in SSR Error Boundary Hydration Markers"
}

CVE-2026-27902 (GCVE-0-2026-27902)

Vulnerability from cvelistv5 – Published: 2026-02-26 00:58 – Updated: 2026-02-26 18:51

Title

Svelte Vulnerable to XSS via HTML Comment Injection in SSR Error Boundary Hydration Markers

Summary

Svelte performance oriented web framework. Prior to version 5.53.5, errors from `transformError` were not correctly escaped prior to being embedded in the HTML output, causing potential HTML injection and XSS if attacker-controlled content is returned from `transformError`. Version 5.53.5 fixes the issue.

Severity ?

5.3 (Medium)


                        
                          CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:L/VI:N/VA:N/SC:H/SI:H/SA:N

CWE

CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Assigner

GitHub_M

References

URL

Tags

	https://github.com/sveltejs/svelte/security/advis…	x_refsource_CONFIRM
	https://github.com/sveltejs/svelte/commit/0298e97…	x_refsource_MISC
	https://github.com/sveltejs/svelte/releases/tag/s…	x_refsource_MISC

Impacted products

	Vendor	Product	Version
	sveltejs	svelte	Affected: >= 5.53.0, < 5.53.5

Show details on NVD website

JSON

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{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-27902",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-02-26T18:51:28.889254Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-02-26T18:51:39.142Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "svelte",
          "vendor": "sveltejs",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 5.53.0, \u003c 5.53.5"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Svelte performance oriented web framework. Prior to version 5.53.5, errors from `transformError` were not correctly escaped prior to being embedded in the HTML output, causing potential HTML injection and XSS if attacker-controlled content is returned from `transformError`. Version 5.53.5 fixes the issue."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "HIGH",
            "attackRequirements": "PRESENT",
            "attackVector": "NETWORK",
            "baseScore": 5.3,
            "baseSeverity": "MEDIUM",
            "privilegesRequired": "NONE",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "HIGH",
            "subIntegrityImpact": "HIGH",
            "userInteraction": "PASSIVE",
            "vectorString": "CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:L/VI:N/VA:N/SC:H/SI:H/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "NONE",
            "vulnConfidentialityImpact": "LOW",
            "vulnIntegrityImpact": "NONE"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-79",
              "description": "CWE-79: Improper Neutralization of Input During Web Page Generation (\u0027Cross-site Scripting\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-02-26T00:58:54.604Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/sveltejs/svelte/security/advisories/GHSA-qgvg-pr8v-6rr3",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/sveltejs/svelte/security/advisories/GHSA-qgvg-pr8v-6rr3"
        },
        {
          "name": "https://github.com/sveltejs/svelte/commit/0298e979371bb583855c9810db79a70a551d22b9",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/sveltejs/svelte/commit/0298e979371bb583855c9810db79a70a551d22b9"
        },
        {
          "name": "https://github.com/sveltejs/svelte/releases/tag/svelte%405.53.5",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/sveltejs/svelte/releases/tag/svelte%405.53.5"
        }
      ],
      "source": {
        "advisory": "GHSA-qgvg-pr8v-6rr3",
        "discovery": "UNKNOWN"
      },
      "title": "Svelte Vulnerable to XSS via HTML Comment Injection in SSR Error Boundary Hydration Markers"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-27902",
    "datePublished": "2026-02-26T00:58:54.604Z",
    "dateReserved": "2026-02-24T15:19:29.718Z",
    "dateUpdated": "2026-02-26T18:51:39.142Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

Action not permitted

GHSA-QGVG-PR8V-6RR3

CVE-2026-27902 (GCVE-0-2026-27902)

Tags

Sightings

Nomenclature