CVE Intelligence
Medium

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

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.

Published Oct 16, 2026 · Updated Oct 16, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: redhat

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.
How the score was calculated
  • Technical severity (medium)+3

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation
Not confirmed
Not in CISA KEV — an absence of record, not proof it is unexploited.
EPSS FIRST
—
No EPSS score.
Affects
Red Hat
Hardened Images and 6 more
CVSS base
5.3
Medium · 2 source(s)

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

  1. Identify exposed assets running the affected vendor/product/version combinations (Red Hat Hardened Images, Red Hat Red Hat Enterprise Linux 10, Red Hat Red Hat Enterprise Linux 6…).
  2. The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
  3. No fix documented in the sources: reduce exposure and monitor the vendor advisory.
  4. Exploitation requires user interaction: tighten email/web filtering and warn affected users.
  5. Search available logs for exploit probes, errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

VendorProductVersionsStatusSource
Red Hat Hardened Images versions not specified by the source Vulnerable CVE Program (cve.org) e CISA ADP
Red Hat Red Hat Enterprise Linux 10 versions not specified by the source Vulnerable CVE Program (cve.org) e CISA ADP
Red Hat Red Hat Enterprise Linux 6 versions not specified by the source Vulnerable CVE Program (cve.org) e CISA ADP
Red Hat Red Hat Enterprise Linux 7 versions not specified by the source Vulnerable CVE Program (cve.org) e CISA ADP
Red Hat Red Hat Enterprise Linux 8 versions not specified by the source Vulnerable CVE Program (cve.org) e CISA ADP
Red Hat Red Hat Enterprise Linux 9 versions not specified by the source Vulnerable CVE Program (cve.org) e CISA ADP
Red Hat Red Hat OpenShift Container Platform 4 versions not specified by the source Vulnerable CVE Program (cve.org) e CISA ADP

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector
Network
Attack complexity
High
Privileges required
None
User interaction
Required
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

ScoreVersionSeverityExpl.ImpactScored by
5.3 CVSS 3.1 Medium 1.6 3.6 secalert@redhat.com via NIST National Vulnerability Database
5.3 CVSS 3.1 Medium — — redhat via CVE Program (cve.org) e CISA ADP
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:H (score shown at the top: secalert@redhat.com)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-1050

Other CVEs with this weakness →

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

  • Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
web/proxy/WAF logsnetwork IDS/IPS

Timeline

What happened to this CVE, newest first.

  • 2026
  • Affected products added · red hat/red hat enterprise linux 10, red hat/red hat enterprise linux 6, red hat/red hat enterprise linux 7, red hat/red
    Oct 16, 2026 · CVE Program (cve.org) e CISA ADP
  • Record published
    Oct 16, 2026
  • CVSS changed · 5.3
    Oct 16, 2026 · NIST National Vulnerability Database
  • Source status changed · → Awaiting Analysis
    Oct 16, 2026 · NIST National Vulnerability Database
  • Record created in this database
    Oct 16, 2026 · Alertas do Telegram
  • CVE published
    Oct 16, 2026 · redhat

Source activity

Repeated readings are counted rather than listed.

  • 1× References added · Oct 16, 2026 – Oct 16, 2026
  • 1× Official description updated · Oct 16, 2026 – Oct 16, 2026

References

2 on the record

Elsewhere on this site

Red Hat
every CVE for this vendor
CWE-1050
other pages naming this weakness

Related CVEs (same products)

  • CVE-2026-89096 Nfs-utils: nfs-utils: denial of service via memory leak in rpc.statd 24m
  • CVE-2026-89088 Parted: parted: denial of service via heap buffer overflow during fat16 resize 24m
  • CVE-2026-89085 Parted: parted: heap-based buffer overflow via crafted fat32 filesystem image 24m
  • CVE-2026-111802 Nautilus: nautilus: arbitrary file deletion via trash symlink 24m
  • CVE-2026-17591 Libarchive: libarchive: use-after-free via aliased mac metadata copy 24m
  • CVE-2026-62438 Gimp: gimp: paa integer overflow out-of-bounds read 1h

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

  • No FIRST EPSS score.
  • No fixed version, patch or mitigation documented.
  • No CISA SSVC assessment.
  • No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
  • No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
  • No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-85977 is "Libtirpc: libtirpc: denial of service via unbounded memory allocation during portmapper response decoding", rated Medium. It affects Hardened Images (Red Hat); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 5.3 describes technical severity. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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