Vulnerabilities in fzf software | CERT Polska

Description

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

The vulnerability CVE-2026-53432: fzf is vulnerable to Integer Overflow leading to crash in FuzzyMatchV2 function. 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 vulnerability 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.

These issues were fixed in version 0.73.1.

Credits

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

More about the coordinated vulnerability disclosure process at CERT Polska can be found at cert.pl/en/cvd/.