CVE-2026-85977
Description
A flaw was found in libtirpc. A remote attacker can exploit this vulnerability by sending specially crafted PMAPPROC_DUMP replies to a client application that uses the pmap_getmaps() function against an attacker-controlled host. This unbounded decoding can lead to excessive memory and CPU allocation, causing the client process to experience a Denial of Service (DoS) due to resource exhaustion.
Statement
This Moderate availability flaw in libtirpc affects client applications that utilize the pmap_getmaps() function against attacker-controlled or spoofed endpoints. While exploitable over the network without authentication, successful exploitation requires the vulnerable client-side portmapper path to be actively used, limiting its broad applicability compared to typical remote denial-of-service vulnerabilities. The impact is confined to resource exhaustion of the client process.
Mitigation
To mitigate this issue, avoid configuring applications that use `pmap_getmaps()` to query untrusted or attacker-controlled portmapper services. If such functionality is essential, restrict network access for services utilizing `pmap_getmaps()` to only trusted hosts via firewall rules. Additionally, consider isolating client applications that call `pmap_getmaps()` into constrained environments to limit the impact of potential resource exhaustion.
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).
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 | High | N/A | High |
| 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:H/PR:N/UI:R/S:U/C:N/I:N/A:H
cve.org: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:H
Acknowledgements
This issue was discovered by Found by AISLE in partnership with Red Hat.
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