CVE-2026-53433

Summary

fzf is vulnerable to a Denial of Service (DoS) due to inefficient HTTP body processing in the –listen mode due to inefficient HTTP body processing using repeated string concatenation, resulting in quadratic time complexity (O(n²)). A crafted POST request with many small segments can trigger excessive CPU usage during request handling.This allows a single malicious request to monopolize the single‑threaded HTTP server, blocking all other clients and resulting in denial of service.

This issue was fixed in version 0.73.1.

Affected Software

VendorProductVersion RangeStatus
fzffzf0 < 0.73.1affected

Weaknesses

  • CWE-407: CWE-407 Inefficient Algorithmic Complexity

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

References