CVE-2026-27125 (GCVE-0-2026-27125)

Vulnerability from cvelistv5 – Published: 2026-02-20 22:29 – Updated: 2026-02-20 22:29
VLAI?
Title
Svelte SSR attribute spreading includes inherited properties from prototype chain
Summary
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.
Severity ?
5.3 (Medium)
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
CWE
  • CWE-915 - Improperly Controlled Modification of Dynamically-Determined Object Attributes
Assigner
References
Impacted products
Vendor Product Version
sveltejs svelte Affected: < 5.51.5
Create a notification for this product.
Show details on NVD website
To clipboard 

{
  "containers": {
    "cna": {
      "affected": [
        {
          "product": "svelte",
          "vendor": "sveltejs",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 5.51.5"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "svelte performance oriented web framework. Prior to 5.51.5, in server-side rendering, attribute spreading on elements (e.g. \u003cdiv {...attrs}\u003e) enumerates inherited properties from the object\u0027s prototype chain rather than only own properties. In environments where Object.prototype has already been polluted \u2014 a precondition outside of Svelte\u0027s control \u2014 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."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "HIGH",
            "attackRequirements": "PRESENT",
            "attackVector": "NETWORK",
            "baseScore": 5.3,
            "baseSeverity": "MEDIUM",
            "privilegesRequired": "LOW",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "HIGH",
            "subIntegrityImpact": "HIGH",
            "userInteraction": "NONE",
            "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",
            "vulnAvailabilityImpact": "NONE",
            "vulnConfidentialityImpact": "LOW",
            "vulnIntegrityImpact": "LOW"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-915",
              "description": "CWE-915: Improperly Controlled Modification of Dynamically-Determined Object Attributes",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-02-20T22:29:45.364Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/sveltejs/svelte/security/advisories/GHSA-crpf-4hrx-3jrp",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/sveltejs/svelte/security/advisories/GHSA-crpf-4hrx-3jrp"
        },
        {
          "name": "https://github.com/sveltejs/svelte/commit/73098bb26c6f06e7fd1b0746d817d2c5ee90755f",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/sveltejs/svelte/commit/73098bb26c6f06e7fd1b0746d817d2c5ee90755f"
        },
        {
          "name": "https://github.com/sveltejs/svelte/releases/tag/svelte@5.51.5",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/sveltejs/svelte/releases/tag/svelte@5.51.5"
        }
      ],
      "source": {
        "advisory": "GHSA-crpf-4hrx-3jrp",
        "discovery": "UNKNOWN"
      },
      "title": "Svelte SSR attribute spreading includes inherited properties from prototype chain"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-27125",
    "datePublished": "2026-02-20T22:29:45.364Z",
    "dateReserved": "2026-02-17T18:42:27.043Z",
    "dateUpdated": "2026-02-20T22:29:45.364Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




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.