RHSA-2026:58822: Important: fence-agents security update

Published Aug 24, 2026
·
Updated

Important: fence-agents security update

Other sources

The fence-agents packages provide a collection of scripts for handling remote power management for cluster devices. They allow failed or unreachable nodes to be forcibly restarted and removed from the cluster. Security Fix(es): pyasn1: pyasn1: Denial of Service via crafted ASN.1 REAL values (CVE-2026-59886) For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Red Hat

Affected Software

21 affected componentsFixes available
Red Hat Red Hat Enterprise Linux for x86_64 - Extended Life Cycle Long Life
Red Hat Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions
Red Hat Red Hat Enterprise Linux High Availability for x86_64 - Update Services for SAP Solutions
Red Hat Red Hat Enterprise Linux High Availability for Power LE - Update Services for SAP Solutions
Red Hat Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions
Red Hat Red Hat Enterprise Linux Server - TUS
Red Hat Red Hat Enterprise Linux High Availability for x86_64 - Extended Life Cycle Long Life
Red Hat Red Hat Enterprise Linux High Availability for x86_64 - Telecommunications Update Service
redhat/fence-agents<4.2.1-112.el8_8.21
4.2.1-112.el8_8.21
redhat/fence-agents-all<4.2.1-112.el8_8.21
4.2.1-112.el8_8.21
redhat/fence-agents-amt-ws<4.2.1-112.el8_8.21
4.2.1-112.el8_8.21
redhat/fence-agents-apc<4.2.1-112.el8_8.21
4.2.1-112.el8_8.21
redhat/fence-agents-apc-snmp<4.2.1-112.el8_8.21
4.2.1-112.el8_8.21
redhat/fence-agents-bladecenter<4.2.1-112.el8_8.21
4.2.1-112.el8_8.21
redhat/fence-agents-brocade<4.2.1-112.el8_8.21
4.2.1-112.el8_8.21
redhat/fence-agents-cisco-mds<4.2.1-112.el8_8.21
4.2.1-112.el8_8.21
redhat/fence-agents-cisco-ucs<4.2.1-112.el8_8.21
4.2.1-112.el8_8.21
redhat/fence-agents-common<4.2.1-112.el8_8.21
4.2.1-112.el8_8.21
redhat/fence-agents-compute<4.2.1-112.el8_8.21
4.2.1-112.el8_8.21
redhat/fence-agents-drac5<4.2.1-112.el8_8.21
4.2.1-112.el8_8.21
redhat/fence-agents-all<4.2.1-112.el8_8.21
4.2.1-112.el8_8.21

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade redhat/fence-agents to a version that resolves this vulnerability.

    Fixed in 4.2.1-112.el8_8.21
  2. Upgrade

    Upgrade redhat/fence-agents-all to a version that resolves this vulnerability.

    Fixed in 4.2.1-112.el8_8.21
  3. Upgrade

    Upgrade redhat/fence-agents-amt-ws to a version that resolves this vulnerability.

    Fixed in 4.2.1-112.el8_8.21
  4. Upgrade

    Upgrade redhat/fence-agents-apc to a version that resolves this vulnerability.

    Fixed in 4.2.1-112.el8_8.21
  5. Upgrade

    Upgrade redhat/fence-agents-apc-snmp to a version that resolves this vulnerability.

    Fixed in 4.2.1-112.el8_8.21
  6. Upgrade

    Upgrade redhat/fence-agents-bladecenter to a version that resolves this vulnerability.

    Fixed in 4.2.1-112.el8_8.21
  7. Upgrade

    Upgrade redhat/fence-agents-brocade to a version that resolves this vulnerability.

    Fixed in 4.2.1-112.el8_8.21
  8. Upgrade

    Upgrade redhat/fence-agents-cisco-mds to a version that resolves this vulnerability.

    Fixed in 4.2.1-112.el8_8.21
  9. Upgrade

    Upgrade redhat/fence-agents-cisco-ucs to a version that resolves this vulnerability.

    Fixed in 4.2.1-112.el8_8.21
  10. Upgrade

    Upgrade redhat/fence-agents-common to a version that resolves this vulnerability.

    Fixed in 4.2.1-112.el8_8.21
  11. Upgrade

    Upgrade redhat/fence-agents-compute to a version that resolves this vulnerability.

    Fixed in 4.2.1-112.el8_8.21
  12. Upgrade

    Upgrade redhat/fence-agents-drac5 to a version that resolves this vulnerability.

    Fixed in 4.2.1-112.el8_8.21
  13. Upgrade

    Upgrade pyasn1 to a version that resolves this vulnerability.

    Patch CVE-2026-59886

Event History

Aug 24, 2026
Advisory Published
via Red Hat·12:00 AM
Data Sourced
via Red Hat·12:00 AM
RemedyDescriptionAffected Software
Advisory Published
via Red Hat·06:03 AM
Data Sourced
via Red Hat·06:03 AM
Severity

Frequently Asked Questions

1

Which systems are in scope for this update?

The advisory covers the fence-agents package collection on the listed Red Hat Enterprise Linux x86_64 and Power LE offerings, including High Availability, Update Services for SAP Solutions, TUS, and Extended Life Cycle Long Life variants.

2

What component is affected by the reported flaw?

The reported issue is CVE-2026-59886 in pyasn1. The stated impact is denial of service through crafted ASN.1 REAL values.

3

Why could this matter in a cluster environment?

fence-agents provides remote power-management scripts that can forcibly restart failed or unreachable nodes and remove them from a cluster. A denial-of-service condition affecting its dependency may be operationally significant where these agents are used for cluster fencing.

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