CVE-2026-83536
Description
A flaw was found in openstack-network-exporter. The HTTP server within the component is configured without essential timeout settings, such as ReadHeaderTimeout. This vulnerability allows an unauthenticated, remote attacker to initiate multiple slow HTTP header connections. By trickling header bytes, the attacker can exhaust server resources, specifically file descriptors, leading to a Denial of Service (DoS) that prevents legitimate Prometheus metric scraping and alerting.
Statement
This vulnerability is rated as having Moderate impact because it only results in a denial of service against the telemetry endpoint, without affecting data confidentiality, data integrity, or core OpenStack services. In standard Red Hat OpenStack Services on OpenShift deployments, openstack-network-exporter is utilized to provide cluster monitoring data rather than handling user-facing traffic or critical control operations. While an unauthenticated network adversary could exhaust available socket connections by slowly transmitting HTTP requests, the disruption is limited to metric collection and alerting for network services.
Mitigation
Restrict network access to the `openstack-network-exporter` service. Configure firewall rules to limit incoming connections to port 1981 (the default port for the exporter) only from trusted hosts or networks that require access for Prometheus scraping. This will reduce the attack surface by preventing unauthenticated adjacent attackers from reaching the service. Applying firewall rules may require restarting network services or the firewall daemon to take effect.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.3 | N/A | 5.3 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | None | N/A | None |
| Integrity Impact | None | N/A | None |
| Availability Impact | Low | N/A | Low |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Red Hat CVSS v3 Score Explanation
Backfilled from source audit finding cited in comment_zero
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory); DoS: Resource Consumption (Other)
If an attacker can trigger the allocation of the limited resources, but the number or size of the resources is not controlled, then the most common result is denial of service. This would prevent valid users from accessing the product, and it could potentially have an impact on the surrounding environment, i.e., the product may slow down, crash due to unhandled errors, or lock out legitimate users. For example, a memory exhaustion attack against an application could slow down the application as well as its host operating system.
Access Control,Other
Technical Impact: Bypass Protection Mechanism; Other
In some cases it may be possible to force the product to "fail open" in the event of resource exhaustion. The state of the product -- and possibly the security functionality - may then be compromised.
Frequently Asked Questions
Not sure what something means? Check out our Security Glossary.
Want to get errata notifications? Sign up here.
