CVE-2025-27421: Goroutine Leak in Abacus SSE Implementation
Description
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.
Classification
CVE ID: CVE-2025-27421
CVSS Base Severity: HIGH
CVSS Base Score: 7.5
CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Problem Types
CWE-400: Uncontrolled Resource Consumption CWE-772: Missing Release of Resource after Effective LifetimeAffected Products
Vendor: JasonLovesDoggo
Product: abacus
Exploit Prediction Scoring System (EPSS)
EPSS Score: 0.06% (probability of being exploited)
EPSS Percentile: 14.11% (scored less or equal to compared to others)
EPSS Date: 2025-04-01 (when was this score calculated)
Stakeholder-Specific Vulnerability Categorization (SSVC)
SSVC Exploitation: poc
SSVC Technical Impact: partial
SSVC Automatable: true
References
https://nvd.nist.gov/vuln/detail/CVE-2025-27421https://github.com/JasonLovesDoggo/abacus/security/advisories/GHSA-vh64-54px-qgf8
https://github.com/JasonLovesDoggo/abacus/commit/898ff1204e11317cc161240b660e63eed5a72b33