In Oryx CycloneTCP 1.9.6, TCP ISNs are improperly random.
Priority MEDIUM 44CWE-330Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA.
Summary
In Oryx CycloneTCP 1.9.6, TCP ISNs are improperly random.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.01083 65th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- 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 |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:oryx-embedded:cyclonetcp:1.9.6:*:*:*:*:*:*:* | 1.9.6 | Vulnerable | Oryx-embedded |
- cpe:2.3:a:oryx-embedded:cyclonetcp:1.9.6:*:*:*:*:*:*:* Versions 1.9.6 Vulnerable ·Oryx-embedded
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2020-27631
- 2026-10-03 Alias added: GHSA-gvwh-h9wm-jvg4
References
More Oryx-embedded Cyclonetcp vulnerabilities
- TI-2021-08434 Oryx Embedded CycloneTCP 1.7.6 to 2.0.0, fixed in 2.0.2, is affected by incorrect input… CVSS 3.1HIGH 7.5
Sources
- CVE-2020-27631 · CVE Program
- CVE-2020-27631 · NVD
- FIRST EPSS
- GHSA-gvwh-h9wm-jvg4 · 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