CVE-2026-84890: undici vulnerable to Denial of Service via unbounded decompression of compressed responses
The interceptors.decompress() interceptor decompresses HTTP response bodies according to the untrusted Content-Encoding header. The number of decompression layers is capped at 5, but the total decompressed output size is not bounded and there is no option to limit it. A malicious or faulty upstream can return a small compressed payload (a compression bomb) that expands to hundreds of megabytes or gigabytes in client memory, exhausting memory and causing the Node.js process to crash or become unresponsive. Any application using the decompress interceptor to read responses from untrusted or compromised upstreams is affected.
References
- cna.openjsf.org/security-advisories.html
- github.com/advisories/GHSA-3xpg-4rpp-hhhm
- github.com/nodejs/undici/commit/2c7d7e1227043c644c4c32cfd1e276f4fd4fcb11
- github.com/nodejs/undici/commit/7aac7f12f757844763c8b8f1ab6e305e80d55838
- github.com/nodejs/undici/releases/tag/v7.29.1
- github.com/nodejs/undici/releases/tag/v8.10.2
- github.com/nodejs/undici/security/advisories/GHSA-3xpg-4rpp-hhhm
- nvd.nist.gov/vuln/detail/CVE-2026-84890
Code Behaviors & Features
Detect and mitigate CVE-2026-84890 with GitLab Dependency Scanning
Secure your software supply chain by verifying that all open source dependencies used in your projects contain no disclosed vulnerabilities. Learn more about Dependency Scanning →