Goroutine Leak in Abacus SSE Implementation
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-400.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| JasonLovesDoggo | abacus | before 1.4.0 | 1.4.0 | Patch available | CNA |
| — | github.com/jasonlovesdoggo/abacus (Go) | before 0.0.0-20250302043802-898ff1204e11 | 0.0.0-20250302043802-898ff1204e11 | Patch available | GHSA-vh64-54px-qgf8 |
- abacus VendorJasonLovesDoggo Affected before 1.4.0 Fixed in 1.4.0 Patch available CNA
- github.com/jasonlovesdoggo/abacus (Go) Vendor— Affected before 0.0.0-20250302043802-898ff1204e11 Fixed in 0.0.0-20250302043802-898ff1204e11 Patch available GHSA-vh64-54px-qgf8
Remediation
- Fix · CNA abacus (JasonLovesDoggo) Fixed in 1.4.0
- Fix · GHSA-vh64-54px-qgf8 github.com/jasonlovesdoggo/abacus (Go) Fixed in 0.0.0-20250302043802-898ff1204e11 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2025-27421
- 2026-10-03 Alias added: GHSA-vh64-54px-qgf8
References
Other 5
- https://github.com/JasonLovesDoggo/abacus/security/advisories/GHSA-vh64-54px-qgf8
- https://github.com/JasonLovesDoggo/abacus/commit/898ff1204e11317cc161240b660e63eed5a72b33
- https://github.com/JasonLovesDoggo/abacus/commit/78fdb9b48b7f6d08ed0cd41077509c0a97071552
- https://github.com/JasonLovesDoggo/abacus
- https://pkg.go.dev/vuln/GO-2025-3498
More JasonLovesDoggo vulnerabilities
- TI-2026-34129 Caddy Defender trusted proxy client IP bypass CVSS 3.1HIGH 8.2
Sources
- CVE-2025-27421 · CVE Program
- CVE-2025-27421 · NVD
- FIRST EPSS
- GHSA-vh64-54px-qgf8 · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences