CVE-2026-94640
Description
A flaw was found in rpcbind. This vulnerability allows a remote, unauthenticated attacker to cause a Denial of Service (DoS) by sending a large number of unique requests. The rpcbind service records previously unseen RPC (Remote Procedure Call) statistics in unbounded in-memory lists, leading to persistent memory growth and increased CPU usage. This can degrade or exhaust service availability.
Mitigation
Restrict network access to the `rpcbind` service on port 111 to trusted systems. This can be achieved by configuring firewall rules to limit inbound connections. For example, using `firewalld` on Red Hat Enterprise Linux:
bash
# To allow access only from a specific trusted network (e.g., 192.168.1.0/24)
firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="192.168.1.0/24" port port="111" protocol="tcp" accept'
firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="192.168.1.0/24" port port="111" protocol="udp" accept'
firewall-cmd --reload
If `rpcbind` is only required for local services, ensure it is configured to listen only on the loopback interface or is otherwise protected from external network exposure. Applying these firewall rules will take effect immediately upon `firewall-cmd --reload` and may temporarily interrupt existing connections to `rpcbind`.
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 | 7.5 | N/A | 7.5 |
| 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 | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
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.
Acknowledgements
This issue was discovered by Found by AISLE in partnership with Red Hat.
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