Improper Cleanup on Thrown Exception Affecting bandit package, versions >=1.9.0 <1.14.0
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-HEX-BANDIT-21755438
- published27 Oct 2026
- disclosed26 Oct 2026
- creditUnknown
Introduced: 26 Oct 2026
NewCVE-2026-111103 (opens in a new tab)How to fix?
Upgrade bandit to version 1.14.0 or higher.
Overview
bandit is a HTTP server for Plug and WebSock apps.
Affected versions of this package are vulnerable to Improper Cleanup on Thrown Exception via the HTTP/2 handler of mtrudel bandit allows an unauthenticated remote attacker to bypass per-connection resource limits via a single TCP write that carries several frames, one of which raises a stream error. When a stream error occurs mid-chunk, Bandit.HTTP2.Handler.handle_data/3 sends RST_STREAM and rolls back connection state-including stream counts, rapid-reset timestamps, and stream IDs-to before the write while leaving previously opened streams running. By appending an invalid frame to each batch of requests, an attacker causes Bandit to forget active streams, completely bypassing limits like max_concurrent_streams and the rapid-reset limiter.