Authentication Bypass in Apache APISIX jwe-decrypt Plugin

Repository contains a working Python proof-of-concept exploit plus a self-contained lab for CVE-2026-49230, an authentication bypass in Apache APISIX's jwe-decrypt plugin. The main exploit file is exploit.py, which forges a compact JWE token whose header contains a valid consumer kid but whose IV, ciphertext, and GCM tag are attacker-controlled garbage. It then sends two requests to a target route: one without a token to confirm the route is gated, and one with the forged Bearer token to confirm bypass if the target is vulnerable. Successful exploitation results in HTTP 200 from the upstream despite the attacker not knowing the AES secret. The vulnerability described in the repository is a logic bug in APISIX <= 3.16.0 where AES-GCM decryption failure is not properly propagated. As a result, the plugin accepts a token with a resolvable kid even when authentication tag verification fails, forwarding a nil/empty identity header upstream and still allowing the request through. The repo also documents a secondary conditional surface: vulnerable versions expose a GET /apisix/plugin/jwe/encrypt API in plugin code that can mint valid JWEs if separately exposed through APISIX public-api, though the included exploit does not use that endpoint. Repository structure: exploit.py is the primary PoC; README.md, ANALYSIS.md, and EVIDENCE.txt document root cause, version boundaries, and empirical results; lab/setup.sh provisions etcd, APISIX, a consumer, and a protected route; lab/backend.py runs a simple HTTP server that echoes whether the request reached the upstream; lab/config.yaml configures APISIX; lab/teardown.sh cleans up. This is a real exploit repository, not merely a detector, though the payload is basic and hardcoded, making maturity best classified as OPERATIONAL rather than weaponized.