{"answers":{"affected":"12 open source packages ship an affected version, including react-server-dom-parcel, react-server-dom-turbopack and react-server-dom-webpack.","exploited":"There is no known exploitation of CVE-2026-126187 in the wild and no public exploit code.","exposure":"","fix":"Upgrade react-server-dom-parcel to a fixed version for your release line: 19.0.9, 19.1.10, 19.2.9 or 19.3.1.","what":"CVE-2026-126187 is a critical vulnerability in react, published on 10 Nov 2026."},"fix_prompt":"Check this codebase for CVE-2026-126187 and fix it if it is affected.\n\nWhat it is: CVE-2026-126187 is a critical vulnerability in react, published on 10 Nov 2026. \nExploitation: There is no known exploitation of CVE-2026-126187 in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- react-server-dom-parcel (npm): affected from 19.0.0; fixed in 19.0.9\n- react-server-dom-parcel (npm): affected from 19.1.0; fixed in 19.1.10\n- react-server-dom-parcel (npm): affected from 19.2.0; fixed in 19.2.9\n- react-server-dom-parcel (npm): affected from 19.3.0; fixed in 19.3.1\n- react-server-dom-turbopack (npm): affected from 19.0.0; fixed in 19.0.9\n- react-server-dom-turbopack (npm): affected from 19.1.0; fixed in 19.1.10\n- react-server-dom-turbopack (npm): affected from 19.2.0; fixed in 19.2.9\n- react-server-dom-turbopack (npm): affected from 19.3.0; fixed in 19.3.1\n- react-server-dom-webpack (npm): affected from 19.0.0; fixed in 19.0.9\n- react-server-dom-webpack (npm): affected from 19.1.0; fixed in 19.1.10\n- react-server-dom-webpack (npm): affected from 19.2.0; fixed in 19.2.9\n- react-server-dom-webpack (npm): affected from 19.3.0; fixed in 19.3.1\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2026-126187/ (Markdown: https://insights.sbomify.com/CVE-2026-126187/index.md)","id":"CVE-2026-126187","markdown":"https://insights.sbomify.com/CVE-2026-126187/index.md","name":"CVE-2026-126187","record":{"aliases":["GHSA-xqc2-xf4c-x3h3","UBUNTU-CVE-2026-126187"],"analysis":null,"analysis_generated_by":null,"assigner":"GitHub_M","cpe":[],"cvss":{"score":9.5,"severity":"critical","source":"cna","vector":"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"},"cwes":[{"id":"CWE-502","name":"Deserialization of Untrusted Data"}],"description":"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.","ecosystems":["npm"],"exploits":{"exploitdb":0,"first_seen":"2026-11-08","github_poc":3,"max_poc_stars":34,"metasploit":0,"nuclei":0,"refs":[{"date":"2026-11-08T22:51:41Z","kind":"github_poc","ref":"https://github.com/briskets/CVE-2026-126187-poc","stars":34,"title":"CVE-2026-126187 Unauthenticated RCE in React Server Components - PoC and Docker lab for GHSA-xqc2-xf4c-x3h3 / GHSA-673q-mjm6-r5xr"},{"date":"2026-11-12T01:43:48Z","kind":"github_poc","ref":"https://github.com/TahuCryptsi/poc-cve-2026-126187-rsc-usecache-rce","stars":3,"title":"PoC: unauth RCE via Next.js use-cache typed-array framing desync (CVE-2026-126187 / GHSA-xqc2-xf4c-x3h3) | docker compose lab"},{"date":"2026-11-11T21:22:57Z","kind":"github_poc","ref":"https://github.com/rudSarkar/GHSA-673q-mjm6-r5xr","stars":0,"title":"Dockerized remote RCE PoC for GHSA-673q-mjm6-r5xr (Next.js use cache / React Flight, CVE-2026-126187): one unauthenticated request -\u003e code execution, with a patched victim that is immune."}],"tier":"poc_unverified"},"has_fix":true,"headline":"React: Unauthenticated Remote Code Execution in React Server Components","id":"CVE-2026-126187","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"npm","product":null,"products":[],"type":null,"year":"2026"},"n_packages":12,"n_references":15,"next":{"headline":"Active Storage: Possible local file disclosure in Active Storage video previews and analysis","id":"CVE-2026-126188"},"nickname":null,"packages":[{"ecosystem":"npm","fixed":["19.0.9"],"introduced":["19.0.0"],"last_affected":[],"package":"react-server-dom-parcel","purl":null,"source":"GHSA-xqc2-xf4c-x3h3"},{"ecosystem":"npm","fixed":["19.1.10"],"introduced":["19.1.0"],"last_affected":[],"package":"react-server-dom-parcel","purl":null,"source":"GHSA-xqc2-xf4c-x3h3"},{"ecosystem":"npm","fixed":["19.2.9"],"introduced":["19.2.0"],"last_affected":[],"package":"react-server-dom-parcel","purl":null,"source":"GHSA-xqc2-xf4c-x3h3"},{"ecosystem":"npm","fixed":["19.3.1"],"introduced":["19.3.0"],"last_affected":[],"package":"react-server-dom-parcel","purl":null,"source":"GHSA-xqc2-xf4c-x3h3"},{"ecosystem":"npm","fixed":["19.0.9"],"introduced":["19.0.0"],"last_affected":[],"package":"react-server-dom-turbopack","purl":null,"source":"GHSA-xqc2-xf4c-x3h3"},{"ecosystem":"npm","fixed":["19.1.10"],"introduced":["19.1.0"],"last_affected":[],"package":"react-server-dom-turbopack","purl":null,"source":"GHSA-xqc2-xf4c-x3h3"},{"ecosystem":"npm","fixed":["19.2.9"],"introduced":["19.2.0"],"last_affected":[],"package":"react-server-dom-turbopack","purl":null,"source":"GHSA-xqc2-xf4c-x3h3"},{"ecosystem":"npm","fixed":["19.3.1"],"introduced":["19.3.0"],"last_affected":[],"package":"react-server-dom-turbopack","purl":null,"source":"GHSA-xqc2-xf4c-x3h3"},{"ecosystem":"npm","fixed":["19.0.9"],"introduced":["19.0.0"],"last_affected":[],"package":"react-server-dom-webpack","purl":null,"source":"GHSA-xqc2-xf4c-x3h3"},{"ecosystem":"npm","fixed":["19.1.10"],"introduced":["19.1.0"],"last_affected":[],"package":"react-server-dom-webpack","purl":null,"source":"GHSA-xqc2-xf4c-x3h3"},{"ecosystem":"npm","fixed":["19.2.9"],"introduced":["19.2.0"],"last_affected":[],"package":"react-server-dom-webpack","purl":null,"source":"GHSA-xqc2-xf4c-x3h3"},{"ecosystem":"npm","fixed":["19.3.1"],"introduced":["19.3.0"],"last_affected":[],"package":"react-server-dom-webpack","purl":null,"source":"GHSA-xqc2-xf4c-x3h3"}],"prev":{"headline":"Active Storage: Possible arbitrary file read and remote code execution in video previews, analysis and image processing","id":"CVE-2026-126186"},"products":["react"],"published":"2026-11-10","related":[],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CC BY 4.0","name":"GitHub Advisory Database","prefix":"GHSA"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"},{"class":"open","licence":"CC0","name":"PoC-in-GitHub"}],"ssvc":{"automatable":null,"exploitation":null,"technical_impact":null},"state":"PUBLISHED","updated":"2026-11-10","vendors":["react"]},"summary":null,"url":"https://insights.sbomify.com/CVE-2026-126187/"}