## Summary
Oracle Fusion Middleware’s Helidon webserver component contains a vulnerability (CVE-2026-83281) affecting versions 4.0.0 through 4.5.4. It is described as easily exploitable by an unauthenticated remote attacker over TCP, leading to a hang or frequently repeatable crash (complete DoS) of Helidon.
## Technical Details
- Affected component: helidon-webserver (Oracle Fusion Middleware / Helidon)
- Attack prerequisites (per NVD):
- Network access over TCP
- No authentication required (PR:N, UI:N)
- Low complexity (AC:L)
- Likely outcome (per NVD):
- Denial of service via hang or repeatable crash
- CVSS 3.1:
- Base score 7.5
- Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
## Affected
- Oracle Fusion Middleware Helidon helidon-webserver
- Versions: 4.0.0 to 4.5.4 (inclusive)
## Impact
- Availability impact (A:H) with no confidentiality or integrity impact reported (C:N, I:N).
- Remote unauthenticated attackers can cause Helidon to hang or crash repeatedly, resulting in complete DoS.
## Mitigation
1. Upgrade Helidon helidon-webserver to a version not included in 4.0.0–4.5.4 (exact fixed version not provided in the available data).
2. Restrict network exposure of the Helidon webserver so it is not reachable from untrusted networks (since exploitation is AV:N).
3. Monitor for signs of service instability (hangs/crashes) and investigate any repeated crash patterns from remote sources.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H