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

Show details on source website

JSON

To clipboard

{
  "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

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-02-26 18:51 UTC

CWE

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

Assigner

GitHub_M CNA under the mitre root

CNA scorecard C 72/100 over 7830 records in the last 180 days details

References

3 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

1 product

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

Show details on NVD website

JSON

To clipboard

{
  "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	Other

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.

Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

Order JSON

Publication & reservation Sightings KEV catalogs Other timestamps

Loading timeline…

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

Action not permitted