Abacus is a highly scalable and stateless counting API. A critical goroutine leak vulnerability has been identified in the Abacus server's Server-Sent Events (SSE) implementation. The issue occurs when clients disconnect from the /stream endpoint, as the server fails to properly clean up resources and terminate associated goroutines. This leads to resource exhaustion where the server continues running but eventually stops accepting new SSE connections while maintaining high memory usage. The vulnerability specifically involves improper channel cleanup in the event handling mechanism, causing goroutines to remain blocked indefinitely. This vulnerability is fixed in 1.4.0.

AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CWE-400

CWE-772

https://github.com/JasonLovesDoggo/abacus/commit/898ff1204e11317cc161240b660e63eed5a72b33

https://github.com/JasonLovesDoggo/abacus/security/advisories/GHSA-vh64-54px-qgf8