# CVE-2026-23869: React Server Components have a Denial of Service Vulnerability > Attackers can cause denial of service in React Server Components by sending crafted HTTP requests that trigger excessive CPU usage. - **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`) - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 8 Apr 2026 - **Updated:** 15 Jul 2026 - **Also known as:** GHSA-479c-33wc-g2pg ## What is CVE-2026-23869? CVE-2026-23869 is a high-severity denial of service vulnerability in Meta react-server-dom-parcel, published on 8 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim. ### Official description A denial of service vulnerability exists in React Server Components, affecting the following packages: react-server-dom-parcel, react-server-dom-turbopack and react-server-dom-webpack (versions 19.0.0 through 19.0.4, 19.1.0 through 19.1.5, and 19.2.0 through 19.2.4). The vulnerability is triggered by sending specially crafted HTTP requests to Server Function endpoints.The payload of the HTTP request causes excessive CPU usage for up to a minute ending in a thrown error that is catchable. Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling), CWE-502 (Deserialization of Untrusted Data), CWE-400 (Uncontrolled Resource Consumption) ## Which versions are affected by CVE-2026-23869? 18 open source packages ship an affected version, including react-server-dom-parcel, react-server-dom-turbopack and react-server-dom-webpack. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `react-server-dom-parcel` | npm | From 19.0.0 | 19.0.5 | | `react-server-dom-parcel` | npm | From 19.0.0 | 19.0.5 | | `react-server-dom-parcel` | npm | From 19.1.0 | 19.1.6 | | `react-server-dom-parcel` | npm | From 19.1.0 | 19.1.6 | | `react-server-dom-parcel` | npm | From 19.2.0 | 19.2.5 | | `react-server-dom-parcel` | npm | From 19.2.0 | 19.2.5 | | `react-server-dom-turbopack` | npm | From 19.0.0 | 19.0.5 | | `react-server-dom-turbopack` | npm | From 19.0.0 | 19.0.5 | | `react-server-dom-turbopack` | npm | From 19.1.0 | 19.1.6 | | `react-server-dom-turbopack` | npm | From 19.1.0 | 19.1.6 | | `react-server-dom-turbopack` | npm | From 19.2.0 | 19.2.5 | | `react-server-dom-turbopack` | npm | From 19.2.0 | 19.2.5 | | `react-server-dom-webpack` | npm | From 19.0.0 | 19.0.5 | | `react-server-dom-webpack` | npm | From 19.0.0 | 19.0.5 | | `react-server-dom-webpack` | npm | From 19.1.0 | 19.1.6 | | `react-server-dom-webpack` | npm | From 19.1.0 | 19.1.6 | | `react-server-dom-webpack` | npm | From 19.2.0 | 19.2.5 | | `react-server-dom-webpack` | npm | From 19.2.0 | 19.2.5 | ## How do I fix CVE-2026-23869? Upgrade react-server-dom-parcel to a fixed version for your release line: 19.0.5, 19.1.6 or 19.2.5. ## Is CVE-2026-23869 being exploited? There is no known exploitation of CVE-2026-23869 in the wild and no public exploit code. Public exploit code: - https://github.com/cybertechajju/CVE-2026-23869-Exploit (github_poc): https://github.com/cybertechajju/CVE-2026-23869-Exploit - POC for CVE-2026-23869 (github_poc): https://github.com/yohannslm/CVE-2026-23869 - Technical troubleshooting repository for fixing infinite rendering vulnerability loops and resource exhaustion threats under CVE-2026-23869 cleanly. (github_poc): https://github.com/shaheryar773/mitigate-cve-2026-23869-react-server-component-loops ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2026-23869 and fix it if it is affected. What it is: CVE-2026-23869 is a high-severity denial of service vulnerability in Meta react-server-dom-parcel, published on 8 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim. Exploitation: There is no known exploitation of CVE-2026-23869 in the wild and no public exploit code. Affected packages and fixed versions: - react-server-dom-parcel (npm): affected from 19.0.0; fixed in 19.0.5 - react-server-dom-parcel (npm): affected from 19.0.0; fixed in 19.0.5 - react-server-dom-parcel (npm): affected from 19.1.0; fixed in 19.1.6 - react-server-dom-parcel (npm): affected from 19.1.0; fixed in 19.1.6 - react-server-dom-parcel (npm): affected from 19.2.0; fixed in 19.2.5 - react-server-dom-parcel (npm): affected from 19.2.0; fixed in 19.2.5 - react-server-dom-turbopack (npm): affected from 19.0.0; fixed in 19.0.5 - react-server-dom-turbopack (npm): affected from 19.0.0; fixed in 19.0.5 - react-server-dom-turbopack (npm): affected from 19.1.0; fixed in 19.1.6 - react-server-dom-turbopack (npm): affected from 19.1.0; fixed in 19.1.6 - react-server-dom-turbopack (npm): affected from 19.2.0; fixed in 19.2.5 - react-server-dom-turbopack (npm): affected from 19.2.0; fixed in 19.2.5 Task: 1. 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. 2. 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. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2026-23869/ (Markdown: https://insights.sbomify.com/CVE-2026-23869/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2026-23869 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-23869 - OSV: https://osv.dev/vulnerability/CVE-2026-23869 --- From sbomify Insights: https://insights.sbomify.com/CVE-2026-23869/ Summaries are generated and may contain mistakes; the official description above is the record.