CVE-2026-23996

Sažetak

FastAPI Api Key provides a backend-agnostic library that provides an API key system. Version 1.1.0 has a timing side-channel vulnerability in verify_key(). The method applied a random delay only on verification failures, allowing an attacker to statistically distinguish valid from invalid API keys by measuring response latencies. With enough repeated requests, an adversary could infer whether a key_id corresponds to a valid key, potentially accelerating brute-force or enumeration attacks. All users relying on verify_key() for API key authentication prior to the fix are affected. Users should upgrade to version 1.1.0 to receive a patch. The patch applies a uniform random delay (min_delay to max_delay) to all responses regardless of outcome, eliminating the timing correlation. Some workarounds are available. Add an application-level fixed delay or random jitter to all authentication responses (success and failure) before the fix is applied and/or use rate limiting to reduce the feasibility of statistical timing attacks.

Reference

CVSS

Base:	3.7
Impact:	1.4
Exploitability:	2.2

Pristup

Vektor	Složenost	Autentikacija
NETWORK	HIGH	NONE

Impact

Povjerljivost	Cjelovitost	Dostupnost
LOW	NONE	NONE

CVSS vektor

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N

Zadnje važnije ažuriranje

26-01-2026 - 15:04

Objavljeno

21-01-2026 - 23:15