Medium · CVSS 5.3CVE-2026-85977

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

Answer in brief

CVE-2026-85977 records a Medium severity (CVSS 5.3) vulnerability in Libtirpc: libtirpc: denial of service via unbounded memory allocation during portmapper response decoding. The current sources do not mark it as known exploited. The current feed maps Red Hat/libtirpc (generic), Red Hat/openshift/ose-rhel-coreos-8 (generic), Red Hat/openshift/ose-rhel-coreos-9 (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Oct 16, 2026Updated Oct 16, 2026Source checked Oct 16, 2026First seen by HOL Oct 16, 2026Material review Oct 16, 2026

Upstream Advisory

Key facts

Risk: Medium · CVSS 5.3
Exploitation: Not marked as known exploited
Affected software: 3 mapped packages or products
Fix availability: Not reported

Why this deserves its current priority

CVSS is 5.3. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Red Hat/libtirpc (generic), Red Hat/openshift/ose-rhel-coreos-8 (generic), Red Hat/openshift/ose-rhel-coreos-9 (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Red Hat/libtirpcgeneric	*	Not reported
Red Hat/openshift/ose-rhel-coreos-8generic	*	Not reported
Red Hat/openshift/ose-rhel-coreos-9generic	*	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Red Hat/libtirpc, Red Hat/openshift/ose-rhel-coreos-8, Red Hat/openshift/ose-rhel-coreos-9.
Review the reported fix. Source-reported workaround: 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.

Evidence timeline and material changes

Published upstream
Oct 16, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Oct 16, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Oct 16, 2026

Sources and claim methodology

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.