CVE-2026-53433CWE-407

Denial of Service in fzf

Medium · published June 30, 2026

CVSS v4.0
5.7
EPSS
0%
Percentile
30.6
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v4.0
5.7 · MEDIUM
Vector
CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
EPSS
0.00378 · 30.6th percentile
Weakness
CWE-407 · Inefficient Algorithmic Complexity
Published
2026-06-30T12:01Z
EPSS history
Timeline
  • 30 JUN 12:01Z
    Denial of Service in fzf
    cvelistv5