Vulnerability in Fzf
CVE-2026-53433
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.
EPSS: 0.002 (11.7th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
Affected products
- Fzf — versions 0
- Junegunn Fzf
Weakness classification (CWE)
References
- cvd@cert.pl (Third Party Advisory, third-party-advisory)
- cvd@cert.pl (Product, product)
- cvd@cert.pl (issue-tracking, Patch)
Frequently asked questions
- What is CVE-2026-53433?
- CVE-2026-53433 is a high-severity vulnerability in Fzf, classified under Inefficient Algorithmic Complexity. CVSS score: 7.5/10. Published 2026-06-30.
- How severe is CVE-2026-53433?
- High severity. CVSS v3 base score is 7.5 out of 10.