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.
Fixes and workarounds
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.
Source: CNA: redhatAffected products and versions
| Product | Versions | Authority |
|---|---|---|
| Red Hat Hardened Images Red Hat libtirpc-main
https://catalog.redhat.com/software/containers/ |
≥ 1.3.8-0.1.hum1; < * (unaffected, rpm)
Other versions: affected |
CNA: redhat |
| Red Hat Enterprise Linux 10 Red Hat libtirpc
https://access.redhat.com/downloads/content/package-browser/ |
Range not reported
Other versions: affected |
CNA: redhat |
| Red Hat Enterprise Linux 6 Red Hat libtirpc
https://access.redhat.com/downloads/content/package-browser/ |
Range not reported
Other versions: affected |
CNA: redhat |
| Red Hat Enterprise Linux 7 Red Hat libtirpc
https://access.redhat.com/downloads/content/package-browser/ |
Range not reported
Other versions: affected |
CNA: redhat |
| Red Hat Enterprise Linux 8 Red Hat libtirpc
https://access.redhat.com/downloads/content/package-browser/ |
Range not reported
Other versions: affected |
CNA: redhat |
| Red Hat Enterprise Linux 9 Red Hat libtirpc
https://access.redhat.com/downloads/content/package-browser/ |
Range not reported
Other versions: affected |
CNA: redhat |
| Red Hat OpenShift Container Platform 4 Red Hat openshift/ose-rhel-coreos-8
https://access.redhat.com/downloads/content/package-browser/ |
Range not reported
Other versions: affected |
CNA: redhat |
| Red Hat OpenShift Container Platform 4 Red Hat openshift/ose-rhel-coreos-9
https://access.redhat.com/downloads/content/package-browser/ |
Range not reported
Other versions: affected |
CNA: redhat |
| Red Hat OpenShift Container Platform 5 Red Hat openshift/ose-rhel-coreos-9
https://access.redhat.com/downloads/content/package-browser/ |
Range not reported
Other versions: affected |
CNA: redhat |
Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.
CVSS assessments
| Version / score | Vector | Authority |
|---|---|---|
| 3.1 / 5.3 medium |
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:H | CNA: redhat |
Exploit evidence
- https://bugzilla.redhat.com/show_bug.cgi?id=2478979
exploit · ADP: CISA-ADP
References
- https://access.redhat.com/errata/RHSA-2026:80360CNA: redhat · vendor-advisory, x_refsource_REDHAT
- https://access.redhat.com/security/cve/CVE-2026-85977CNA: redhat · vdb-entry, x_refsource_REDHAT
- https://bugzilla.redhat.com/show_bug.cgi?id=2478979CNA: redhat · issue-tracking, x_refsource_REDHAT
- https://bugzilla.redhat.com/show_bug.cgi?id=2478979ADP: CISA-ADP · exploit
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