# CVE-2026-114213: mtrudel bandit WebSocket denial of service via fragmented messages

Source: https://junglewise.ai/threats/cve-2026-114213-allocation-of-resources-without-limits-or-throttling  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-26. Updated: 2026-10-26  
License: CC BY 4.0 with a link back

CVE-2026-114213 · Severity: info · Published 2026-10-26

Bandit is a WebSocket library used in Elixir applications. An unauthenticated attacker can exhaust server memory by sending specially crafted fragmented WebSocket messages, causing a denial of service. A single connection can consume 150 times the configured fragment size limit, potentially allocating 1.2–1.4 GB of memory at default settings.

Technologies: [Mtrudel Bandit](https://junglewise.ai/threats/technologies/mtrudel-bandit). Vendors: [Mtrudel](https://junglewise.ai/threats/vendors/mtrudel).

## Quick answers

**Is CVE-2026-114213 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-114213 being exploited in the wild.

**How severe is CVE-2026-114213?** Informational severity, published 26 October 2026.

**Which products and versions are affected?** Mtrudel Bandit 1.11.0 before 1.14.0.

**Is there a fix for CVE-2026-114213?** Yes: fixed in 1.14.0. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-114213 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-114213?** Check whether you run Mtrudel Bandit at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in 1.14.0

## Technical details

The vulnerability is an unbounded resource allocation in WebSocket fragment reassembly: Bandit.WebSocket.Connection checks max_fragmented_message_size against payload bytes but stores each non-final continuation frame as a separate list cell, with no limit on fragment count. A 1-byte fragment consumes 150–170 bytes of server memory, allowing an attacker to exceed the configured limit by 150×. Ping frames can reset the idle timeout, keeping the connection alive and memory allocated.

## Affected products

- mtrudel bandit 1.11.0 before 1.14.0

## Timeline

- 2026-10-26: disclosed

## References

- [https://repo.hex.pm/](https://repo.hex.pm/)
- [https://github.com/](https://github.com/)

## Related threats

- [mtrudel bandit resource exhaustion in HTTP/2 request body reader](https://junglewise.ai/threats/cve-2026-116078-allocation-of-resources-without-limits-or-throttling)
- [mtrudel bandit HTTP/2 stream resource exhaustion](https://junglewise.ai/threats/cve-2026-115269-allocation-of-resources-without-limits-or-throttling)
- [mtrudel bandit inefficient algorithmic complexity in header parser](https://junglewise.ai/threats/cve-2026-113436-inefficient-algorithmic-complexity-vulnerability-in-the-header)
- [mtrudel bandit HTTP/2 handler resource limit bypass](https://junglewise.ai/threats/cve-2026-111103-improper-cleanup-on-thrown-exception-vulnerability-in-the-http-2)
- [mtrudel bandit HTTP/1.1 chunked body denial of service](https://junglewise.ai/threats/cve-2026-111101-allocation-of-resources-without-limits-or-throttling)