Allocation of Resources Without Limits or Throttling vulnerability in mtrudel bandit allows unauthenticated remote denial of service via memory exhaustion.
The fragment reassembly path in 'Elixir.Bandit.WebSocket.Connection':handle_frame/3 in lib/bandit/websocket/connection.ex appends every incoming Continuation{fin: false} frame's payload to a per-connection iolist with no cumulative size cap. The existing max_frame_size option only bounds individual frames; a peer that streams an unbounded number of continuation frames without ever setting fin=1 grows BEAM heap linearly until the OS or a supervisor kills the process.
Because the accumulation happens before WebSock.handle_in/2 is called, the application has no opportunity to interpose a size check. Phoenix Channels and LiveView both run over WebSock on Bandit, so a stock Phoenix application exposes this surface as soon as it accepts socket connections.
This issue affects bandit: from 0.5.0 before 1.11.0.
CVSS
No CVSS.
References
Configurations
No configuration.
History
02 May 2026, 02:16
| Type | Values Removed | Values Added |
|---|---|---|
| References | () https://github.com/mtrudel/bandit/security/advisories/GHSA-pf94-94m9-536p - |
01 May 2026, 21:16
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2026-05-01 21:16
Updated : 2026-05-05 19:37
NVD link : CVE-2026-42786
Mitre link : CVE-2026-42786
CVE.ORG link : CVE-2026-42786
JSON object : View
Products Affected
No product.
CWE
CWE-770
Allocation of Resources Without Limits or Throttling