CVE-2026-16277
Description
A stack-based buffer overflow was found in rpcbind's rpcinfo utility. When querying a remote rpcbind service with rpcinfo -l, address information returned by the server is copied into a fixed-size buffer without sufficient bounds checking. A malicious or compromised rpcbind server could use this flaw to crash the rpcinfo client, resulting in a denial of service. The highest threat from this vulnerability is to system availability.
Statement
We rate the flaw as Moderate because exploitation requires a user or administrator to actively run rpcinfo -l against a malicious or compromised rpcbind endpoint (UI:R) — it cannot be triggered without that action. The demonstrated impact is limited to a crash of the rpcinfo client process; confidentiality and integrity are not affected, and no reliable code execution has been established.
Mitigation
To mitigate this issue, avoid using the `rpcinfo -l` command against untrusted, attacker-controlled, or compromised `rpcbind` hosts. Restrict the use of the `rpcinfo` utility to trusted internal endpoints or secure test environments only.
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 | 6.5 | N/A | 6.5 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | Required | N/A | Required |
| 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:R/S:U/C:N/I:N/A:H
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: Modify Memory; DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory)
Buffer overflows generally lead to crashes. Other attacks leading to lack of availability are possible, including putting the program into an infinite loop.
Integrity,Confidentiality,Availability,Access Control
Technical Impact: Modify Memory; Execute Unauthorized Code or Commands; Bypass Protection Mechanism
Buffer overflows often can be used to execute arbitrary code, which is usually outside the scope of a program's implicit security policy.
Integrity,Confidentiality,Availability,Access Control,Other
Technical Impact: Modify Memory; Execute Unauthorized Code or Commands; Bypass Protection Mechanism; Other
When the consequence is arbitrary code execution, this can often be used to subvert any other security service.
Acknowledgements
Red Hat would like to thank Aisle Research and Michalis Vasileiadis (GitHub: vmihalis) for reporting this issue.
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