ffuf vulnerability

ffuf is a fast web fuzzer written in Go. Prior to 2.2.0, ffuf allows a malicious target server to cause an out-of-memory denial of service because the response size guard in pkg/runner/simple.go checks only the compressed Content-Length while io.ReadAll reads gzip, brotli, deflate, transparently decompressed, or chunked response bodies without a decompressed-size bound. This issue is fixed in version 2.2.0.

Published 11 Aug 2026Updated 18 Sep 20264 sources
CVSS 7.5

What happened

ffuf is a fast web fuzzer written in Go. Prior to 2.2.0, ffuf allows a malicious target server to cause an out-of-memory denial of service because the response size guard in pkg/runner/simple.go checks only the compressed Content-Length while io.ReadAll reads gzip, brotli, deflate, transparently decompressed, or chunked response bodies without a decompressed-size bound. This issue is fixed in version 2.2.0.

Affected versions

ffuf: < 2.2.0 Fixed: See vendor advisory.

Why it matters

Review the vendor advisory and exposure of the affected product to determine operational impact.

Detection & mitigation

  • Apply vendor-provided updates or mitigations.
  • Review affected product exposure and access logs.

Public PoC references

No public PoC reference has passed the current publication threshold.