November 13, 2026 Follow Egret
CVE-2026-126187 · CVE record: PUBLISHED

React: Unauthenticated Remote Code Execution in React Server Components

react react

React is a JavaScript library for building user interfaces. From 19.0.0 until 19.0.9, 19.1.10, 19.2.9, and 19.3.1, the react-server-dom-webpack, react-server-dom-parcel, and react-server-dom-turbopack packages are vulnerable to unauthenticated remote code execution through crafted payloads targeting frameworks that support React Server Components. The vulnerability only affects extremely rare cases where responses transport multiple typed arrays and an attacker-controlled value. Applications whose React code does not use a server are not affected. Applications that do not use a framework, bundler, or bundler plugin that supports React Server Components are not affected. This issue is fixed in versions 19.0.9, 19.1.10, 19.2.9, and 19.3.1.

Exploitation evidence

Not listed in the latest downloaded CISA KEV catalog. This does not establish an absence of exploitation.

KEV checked 13 Nov 2026, 00:20 Jerusalem · Original catalog ↗

Reported products and versions

react / react

Default status: Not specified

  • affected: >= 19.0.0, < 19.0.9
  • affected: >= 19.1.0, < 19.1.10
  • affected: >= 19.2.0, < 19.2.9
  • affected: >= 19.3.0, < 19.3.1

Fixes and workarounds

No explicit solution text in the downloaded CVE record. Consult the vendor advisory; unaffected version ranges are shown above as reported, not inferred as a patch recommendation.

Sources and related reporting

CVE Program record ↗ · Download tracked evidence as JSON

Monitored source mentions

Shared CVE identifiers link source mentions; they do not establish that the reports describe the same incident.

Observed change timeline

History begins when Egret first downloads each source. It is not the complete upstream CVE history.

12 Nov 2026, 18:20 Jerusalem · EPSS observation updated

Stored EPSS snapshot at this observation.

{
  "date": "2026-11-12",
  "epss": 0.01763,
  "percentile": 0.78362
}
11 Nov 2026, 12:20 Jerusalem · CVE Program record changed

Stored CNA snapshot at this observation.

{
  "containers": {
    "cna": {
      "affected": [
        {
          "product": "react",
          "vendor": "react",
          "versions": [
            {
              "status": "affected",
              "version": ">= 19.0.0, < 19.0.9"
            },
            {
              "status": "affected",
              "version": ">= 19.1.0, < 19.1.10"
            },
            {
              "status": "affected",
              "version": ">= 19.2.0, < 19.2.9"
            },
            {
              "status": "affected",
              "version": ">= 19.3.0, < 19.3.1"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "React is a JavaScript library for building user interfaces. From 19.0.0 until 19.0.9, 19.1.10, 19.2.9, and 19.3.1, the react-server-dom-webpack, react-server-dom-parcel, and react-server-dom-turbopack packages are vulnerable to unauthenticated remote code execution through crafted payloads targeting frameworks that support React Server Components. The vulnerability only affects extremely rare cases where responses transport multiple typed arrays and an attacker-controlled value. Applications whose React code does not use a server are not affected. Applications that do not use a framework, bundler, or bundler plugin that supports React Server Components are not affected. This issue is fixed in versions 19.0.9, 19.1.10, 19.2.9, and 19.3.1."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "LOW",
            "attackRequirements": "PRESENT",
            "attackVector": "NETWORK",
            "baseScore": 9.5,
            "baseSeverity": "CRITICAL",
            "privilegesRequired": "NONE",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "HIGH",
            "subIntegrityImpact": "HIGH",
            "userInteraction": "NONE",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "HIGH",
            "vulnConfidentialityImpact": "HIGH",
            "vulnIntegrityImpact": "HIGH"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-502",
              "description": "CWE-502: Deserialization of Untrusted Data",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-11-10T22:33:57.528Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/react/react/security/advisories/GHSA-xqc2-xf4c-x3h3",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/react/react/security/advisories/GHSA-xqc2-xf4c-x3h3"
        },
        {
          "name": "https://github.com/react/react/pull/37842",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/react/react/pull/37842"
        },
        {
          "name": "https://github.com/react/react/pull/37843",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/react/react/pull/37843"
        },
        {
          "name": "https://github.com/react/react/pull/37844",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/react/react/pull/37844"
        },
        {
          "name": "https://github.com/react/react/pull/37845",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/react/react/pull/37845"
        },
        {
          "name": "https://github.com/react/react/pull/37846",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/react/react/pull/37846"
        },
        {
          "name": "https://github.com/react/react/commit/0c9913ae87283f96e868a8f1c20a3389827632d0",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/react/react/commit/0c9913ae87283f96e868a8f1c20a3389827632d0"
        },
        {
          "name": "https://github.com/react/react/commit/249ac87b0dadea4ba024d1393e5cb60cf1186080",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/react/react/commit/249ac87b0dadea4ba024d1393e5cb60cf1186080"
        },
        {
          "name": "https://github.com/react/react/commit/3d06b4005ac0cf9dec37267f26174adfe6d83611",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/react/react/commit/3d06b4005ac0cf9dec37267f26174adfe6d83611"
        },
        {
          "name": "https://github.com/react/react/commit/611d9217df39cf7b8ac91b2e41fd00555923e904",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/react/react/commit/611d9217df39cf7b8ac91b2e41fd00555923e904"
        },
        {
          "name": "https://github.com/react/react/commit/61aa00df822d0eb76d0362eb8b6fdd3527693efe",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/react/react/commit/61aa00df822d0eb76d0362eb8b6fdd3527693efe"
        },
        {
          "name": "https://github.com/react/react/releases/tag/v19.0.9",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/react/react/releases/tag/v19.0.9"
        },
        {
          "name": "https://github.com/react/react/releases/tag/v19.1.10",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/react/react/releases/tag/v19.1.10"
        },
        {
          "name": "https://github.com/react/react/releases/tag/v19.2.9",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/react/react/releases/tag/v19.2.9"
        },
        {
          "name": "https://github.com/react/react/releases/tag/v19.3.1",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/react/react/releases/tag/v19.3.1"
        }
      ],
      "source": {
        "advisory": "GHSA-xqc2-xf4c-x3h3",
        "discovery": "UNKNOWN"
      },
      "title": "React: Unauthenticated Remote Code Execution in React Server Components"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-126187",
    "datePublished": "2026-11-10T22:33:57.528Z",
    "dateReserved": "2026-11-10T20:07:44.956Z",
    "dateUpdated": "2026-11-10T22:33:57.528Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}
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