Vulnerabilities in fzf software

CERT Polska has received a report about vulnerabilities in fzf software and participated in coordination of their disclosure.

The vulnerabilityCVE-2026-53432: fzf is vulnerable to Integer Overflow leading to crash inFuzzyMatchV2function. When input line length is approximately 2,200,000 bytes and pattern length is 999 bytes, the product overflows. The Go runtime detects the invalid slice bounds and terminates the process immediately with a non-recoverable panic.

The vulnerabilityCVE-2026-53433: fzf is vulnerable to a Denial of Service (DoS) due to inefficient HTTP body processing in the--listenmode 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.

These issues were fixed in version 0.73.1.

We thank Michał Majchrowicz and Marcin Wyczechowski from AFINE Team for the responsible vulnerability report.