PT-2026-53864 · Fzf · Fzf

Marcin Wyczechowski + 1 · Published 2026-06-30 · Updated 2026-06-30 · CVE-2026-53433

Mitre

CVSS v4.0

5.7

Medium

Base vector

AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

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.

Fix

Weakness Enumeration

CWE-407

Related Identifiers

CVE-2026-53433

Affected Products

Fzf

References · 4

• https://nvd.nist.gov/vuln/detail/CVE-2026-53433 · Security Note
• https://github.com/junegunn/fzf · Note
• https://github.com/junegunn/fzf/commit/7963a2c6586c0b9eaa89b8995de8f0e08cf8a4ce · Note
• https://cert.pl/en/posts/2026/06/CVE-2026-53432 · Note