CVE-2026-53433 | fzf is vulnerable to a Denial of Service (DoS) due to ineffi… | CVSS 5.7 MEDIUM

Description

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.

Metadata

CVE ID: CVE-2026-53433
State: PUBLISHED
Assigner: CERT-PL
Reserved: 2026-06-09 11:41 UTC
Published: 2026-06-30 12:01 UTC
Last updated: 2026-06-30 13:32 UTC
Primary CWE: CWE-407
CWE-407 Inefficient Algorithmic Complexity
Vendor / Product: fzf / fzf
Sources: cve.org · NVD

Severity & Metrics

5.7 MEDIUM CVSS 4.0

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

SSVC — CISA Coordinator

Exploitation: none
Automatable: no
Tech. Impact: partial

Affected products (1)

Vendor	Product	Platform	Versions
fzf	fzf	—	0 < 0.73.1

Weakness (CWE)

CWE	Source	Description
CWE-407	cna	CWE-407 Inefficient Algorithmic Complexity

CVSS scores (1)

Score	Severity	Version	Source	Vector
5.7	MEDIUM	4.0	cna	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

References (3)