elixir-grpc grpc_server up to 1.0.9 Stream grpc_stream_h.erl denial of service

Summaryinfo

A vulnerability was found in elixir-grpc grpc_server up to 1.0.9. It has been rated as problematic. This vulnerability affects unknown code of the file grpc_server/src/grpc_stream_h.erl of the component Stream Handler. This manipulation causes denial of service. This vulnerability appears as CVE-2026-123635. The attack may be initiated remotely. There is no available exploit. Upgrading the affected component is advised.

Detailsinfo

A vulnerability has been found in elixir-grpc grpc_server up to 1.0.9 and classified as problematic. Affected by this vulnerability is an unknown function of the file grpc_server/src/grpc_stream_h.erl of the component Stream Handler. The manipulation with an unknown input leads to a denial of service vulnerability. The CWE definition for the vulnerability is CWE-404. The product does not release or incorrectly releases a resource before it is made available for re-use. As an impact it is known to affect availability. The summary by CVE is:

Missing Release of Resource after Effective Lifetime vulnerability in elixir-grpc grpc_server allows a client to stall all later calls on a shared HTTP/2 connection via calls that the server refuses while their DATA frames are in flight. The stream handler grpc_stream_h (grpc_server/src/grpc_stream_h.erl) requests flow from Cowboy only for request data that has arrived. When the server refuses a call early, for example because the body exceeds max_body_size or the method is not implemented, Cowboy drops the DATA frames still in flight for that stream. Their bytes are not returned to the connection flow-control window. After enough refused calls the window is empty. No call on that connection can then send a request body, and each call waits until its deadline. Other connections are not affected. This issue affects grpc_server: from 1.0.0 before 1.1.0.

It is possible to read the advisory at github.com. This vulnerability is known as CVE-2026-123635 since 11/09/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Technical details of the vulnerability are known, but there is no available exploit. The attack technique deployed by this issue is T1499 according to MITRE ATT&CK.

Upgrading to version 1.1.0 eliminates this vulnerability.

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Productinfo

Vendor

• elixir-grpc

Name

• grpc_server

Version

• 1.0.0
• 1.0.1
• 1.0.2
• 1.0.3
• 1.0.4
• 1.0.5
• 1.0.6
• 1.0.7
• 1.0.8
• 1.0.9

CPE 2.3info

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CPE 2.2info

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