# CVE-2026-126187: React: Unauthenticated Remote Code Execution in React Server Components

Status: published. Published: 2026-11-10. Updated: 2026-11-10.

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.

## Remediation

- fix: react-server-dom-parcel (npm): OSV reports a fixed version 19.0.9. Check the advisory for supported release branches. (source: OSV GHSA-xqc2-xf4c-x3h3) — https://github.com/advisories/GHSA-xqc2-xf4c-x3h3
- fix: react-server-dom-parcel (npm): OSV reports a fixed version 19.1.10. Check the advisory for supported release branches. (source: OSV GHSA-xqc2-xf4c-x3h3) — https://github.com/advisories/GHSA-xqc2-xf4c-x3h3
- fix: react-server-dom-parcel (npm): OSV reports a fixed version 19.2.9. Check the advisory for supported release branches. (source: OSV GHSA-xqc2-xf4c-x3h3) — https://github.com/advisories/GHSA-xqc2-xf4c-x3h3
- fix: react-server-dom-parcel (npm): OSV reports a fixed version 19.3.1. Check the advisory for supported release branches. (source: OSV GHSA-xqc2-xf4c-x3h3) — https://github.com/advisories/GHSA-xqc2-xf4c-x3h3
- fix: react-server-dom-turbopack (npm): OSV reports a fixed version 19.0.9. Check the advisory for supported release branches. (source: OSV GHSA-xqc2-xf4c-x3h3) — https://github.com/advisories/GHSA-xqc2-xf4c-x3h3
- fix: react-server-dom-turbopack (npm): OSV reports a fixed version 19.1.10. Check the advisory for supported release branches. (source: OSV GHSA-xqc2-xf4c-x3h3) — https://github.com/advisories/GHSA-xqc2-xf4c-x3h3
- fix: react-server-dom-turbopack (npm): OSV reports a fixed version 19.2.9. Check the advisory for supported release branches. (source: OSV GHSA-xqc2-xf4c-x3h3) — https://github.com/advisories/GHSA-xqc2-xf4c-x3h3
- fix: react-server-dom-turbopack (npm): OSV reports a fixed version 19.3.1. Check the advisory for supported release branches. (source: OSV GHSA-xqc2-xf4c-x3h3) — https://github.com/advisories/GHSA-xqc2-xf4c-x3h3
- fix: react-server-dom-webpack (npm): OSV reports a fixed version 19.0.9. Check the advisory for supported release branches. (source: OSV GHSA-xqc2-xf4c-x3h3) — https://github.com/advisories/GHSA-xqc2-xf4c-x3h3
- fix: react-server-dom-webpack (npm): OSV reports a fixed version 19.1.10. Check the advisory for supported release branches. (source: OSV GHSA-xqc2-xf4c-x3h3) — https://github.com/advisories/GHSA-xqc2-xf4c-x3h3
- fix: react-server-dom-webpack (npm): OSV reports a fixed version 19.2.9. Check the advisory for supported release branches. (source: OSV GHSA-xqc2-xf4c-x3h3) — https://github.com/advisories/GHSA-xqc2-xf4c-x3h3
- fix: react-server-dom-webpack (npm): OSV reports a fixed version 19.3.1. Check the advisory for supported release branches. (source: OSV GHSA-xqc2-xf4c-x3h3) — https://github.com/advisories/GHSA-xqc2-xf4c-x3h3

## Affected products and versions

- react / react: >= 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 (affected). Source: CNA: GitHub_M
-  / react-server-dom-parcel (react-server-dom-parcel): ≥ 19.0.0; < 19.0.9 (affected, semver); OSV events: introduced 19.0.0; fixed 19.0.9. Source: OSV GHSA-xqc2-xf4c-x3h3
-  / react-server-dom-parcel (react-server-dom-parcel): ≥ 19.1.0; < 19.1.10 (affected, semver); OSV events: introduced 19.1.0; fixed 19.1.10. Source: OSV GHSA-xqc2-xf4c-x3h3
-  / react-server-dom-parcel (react-server-dom-parcel): ≥ 19.2.0; < 19.2.9 (affected, semver); OSV events: introduced 19.2.0; fixed 19.2.9. Source: OSV GHSA-xqc2-xf4c-x3h3
-  / react-server-dom-parcel (react-server-dom-parcel): ≥ 19.3.0; < 19.3.1 (affected, semver); OSV events: introduced 19.3.0; fixed 19.3.1. Source: OSV GHSA-xqc2-xf4c-x3h3
-  / react-server-dom-turbopack (react-server-dom-turbopack): ≥ 19.0.0; < 19.0.9 (affected, semver); OSV events: introduced 19.0.0; fixed 19.0.9. Source: OSV GHSA-xqc2-xf4c-x3h3
-  / react-server-dom-turbopack (react-server-dom-turbopack): ≥ 19.1.0; < 19.1.10 (affected, semver); OSV events: introduced 19.1.0; fixed 19.1.10. Source: OSV GHSA-xqc2-xf4c-x3h3
-  / react-server-dom-turbopack (react-server-dom-turbopack): ≥ 19.2.0; < 19.2.9 (affected, semver); OSV events: introduced 19.2.0; fixed 19.2.9. Source: OSV GHSA-xqc2-xf4c-x3h3
-  / react-server-dom-turbopack (react-server-dom-turbopack): ≥ 19.3.0; < 19.3.1 (affected, semver); OSV events: introduced 19.3.0; fixed 19.3.1. Source: OSV GHSA-xqc2-xf4c-x3h3
-  / react-server-dom-webpack (react-server-dom-webpack): ≥ 19.0.0; < 19.0.9 (affected, semver); OSV events: introduced 19.0.0; fixed 19.0.9. Source: OSV GHSA-xqc2-xf4c-x3h3
-  / react-server-dom-webpack (react-server-dom-webpack): ≥ 19.1.0; < 19.1.10 (affected, semver); OSV events: introduced 19.1.0; fixed 19.1.10. Source: OSV GHSA-xqc2-xf4c-x3h3
-  / react-server-dom-webpack (react-server-dom-webpack): ≥ 19.2.0; < 19.2.9 (affected, semver); OSV events: introduced 19.2.0; fixed 19.2.9. Source: OSV GHSA-xqc2-xf4c-x3h3
-  / react-server-dom-webpack (react-server-dom-webpack): ≥ 19.3.0; < 19.3.1 (affected, semver); OSV events: introduced 19.3.0; fixed 19.3.1. Source: OSV GHSA-xqc2-xf4c-x3h3

## Severity and prioritization

- CVSS 4.0: 9.5 (critical); 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; source: CNA: GitHub_M

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: Not available

- Weaknesses: CWE-502

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://github.com/react/react/security/advisories/GHSA-xqc2-xf4c-x3h3 (CNA: GitHub_M; x_refsource_CONFIRM)

- https://github.com/react/react/pull/37842 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/react/react/pull/37843 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/react/react/pull/37844 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/react/react/pull/37845 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/react/react/pull/37846 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/react/react/commit/0c9913ae87283f96e868a8f1c20a3389827632d0 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/react/react/commit/249ac87b0dadea4ba024d1393e5cb60cf1186080 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/react/react/commit/3d06b4005ac0cf9dec37267f26174adfe6d83611 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/react/react/commit/611d9217df39cf7b8ac91b2e41fd00555923e904 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/react/react/commit/61aa00df822d0eb76d0362eb8b6fdd3527693efe (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/react/react/releases/tag/v19.0.9 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/react/react/releases/tag/v19.1.10 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/react/react/releases/tag/v19.2.9 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/react/react/releases/tag/v19.3.1 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/advisories/GHSA-xqc2-xf4c-x3h3 (OSV / GitHub Security Advisories; advisory)

- https://osv.dev/vulnerability/GHSA-xqc2-xf4c-x3h3 (OSV / GitHub Security Advisories; osv)

## Provenance

- CNA: GitHub_M: https://www.cve.org/CVERecord?id=CVE-2026-126187; retrieved 2026-11-10; source updated 2026-11-10

- OSV / GitHub Security Advisories: https://osv.dev/vulnerability/GHSA-xqc2-xf4c-x3h3; retrieved 2026-11-10; source updated 2026-11-10

Revision: c4a11b8c9be5169b475283777ba5bce5e1123c85a45d14b4b281672c852d95d9

Canonical: https://y2.dev/cve/CVE-2026-126187

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