CVE-2026-85977: Libtirpc: libtirpc: denial of service via unbounded memory allocation during portmapper response decoding

Severity: medium (CVSS 5.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-10-16 · updated 2026-10-19
Weakness: CWE-1050

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.

Affected products

Red Hat OpenShift Container Platform 4.18: all versions
Red Hat Enterprise Linux 10: all versions
Red Hat Enterprise Linux 6: all versions
Red Hat Enterprise Linux 7: all versions
Red Hat Enterprise Linux 8: all versions
Red Hat Enterprise Linux 9: all versions
Red Hat Hardened Images: all versions — fixed in 1.3.8-0.1.hum1

How to fix

Upgrade to a fixed version: Red Hat Hardened Images 1.3.8-0.1.hum1. Check the vendor advisory for mitigations.

References

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