sse-channel: SSE Injection via unsanitized event fields
Priority LOW 36CWE-93Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- —
- Confidentiality · integrity · availability
- None · High · None
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub.
Summary
sse-channel is an SSE-implementation which can be used to any node.js http request/response stream. Prior to 4.0.1, implementations that allow user-provided values to be passed to event, retry or id fields are susceptible to event spoofing, where an attacker could inject arbitrary messages into the stream. This vulnerability is fixed in 4.0.1.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00479 41st percentileScored 2026-11-07
Fix Fixed sse-channel (rexxars): 4.0.1sse-channel (npm): 4.0.1
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- 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 |
|---|---|---|---|---|---|
| rexxars | sse-channel | before 4.0.1 | 4.0.1 | Patch available | CNA |
| — | sse-channel (npm) | before 4.0.1 | 4.0.1 | Patch available | GHSA-84hm-wfh8-c5pg |
- sse-channel Vendorrexxars Affected before 4.0.1 Fixed in 4.0.1 Patch available CNA
- sse-channel (npm) Vendor— Affected before 4.0.1 Fixed in 4.0.1 Patch available GHSA-84hm-wfh8-c5pg
Remediation
- Fix · CNA sse-channel (rexxars) Fixed in 4.0.1
- Fix · GHSA-84hm-wfh8-c5pg sse-channel (npm) Fixed in 4.0.1 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2026-44217
- 2026-10-03 Alias added: GHSA-84hm-wfh8-c5pg
References
More rexxars vulnerabilities
- TI-2026-32193 eventsource-encoder: SSE event injection via unsanitized event and id fields CVSS 3.1MEDIUM 5.8
Sources
- CVE-2026-44217 · CVE Program
- CVE-2026-44217 · NVD
- FIRST EPSS
- GHSA-84hm-wfh8-c5pg · 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