RHSA-2026:97288 - Security Advisory

Topic

An update for yggdrasil is now available for Red Hat Enterprise Linux 10.

Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

Description

yggdrasil is a system daemon that subscribes to topics on an MQTT broker and routes any data received on the topics to an appropriate child "worker" process, exchanging data with its worker processes through a D-Bus message broker.

Security Fix(es):

• crypto/x509: Incorrect enforcement of email constraints in crypto/x509 (CVE-2026-27137)

Bug Fix(es) and Enhancement(s):

• [Azure][RHEL-10][yggd]failed to publish message: not Connected (JIRA:RHEL-135848)
• Set the MQTT LastWill message each time the client connects to the broker (JIRA:RHEL-166873)
• Yggdrasil: add "client-id" subcommand to yggctl (JIRA:RHEL-178895)
• Yggdrasil SQL Injection Through DBus (JIRA:RHEL-90808)
• fix: set HTTP client timeout and max idle connection timeout (JIRA:RHEL-168913)

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.

Additional Changes:

For detailed information on changes in this release, see the Red Hat Enterprise Linux 10 Release Notes linked from the References section.

Solution

For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

Affected Products

• Red Hat Enterprise Linux for x86_64 10 x86_64
• Red Hat Enterprise Linux for IBM z Systems 10 s390x
• Red Hat Enterprise Linux for Power, little endian 10 ppc64le
• Red Hat Enterprise Linux for ARM 64 10 aarch64
• Red Hat CodeReady Linux Builder for x86_64 10 x86_64
• Red Hat CodeReady Linux Builder for Power, little endian 10 ppc64le
• Red Hat CodeReady Linux Builder for ARM 64 10 aarch64
• Red Hat CodeReady Linux Builder for IBM z Systems 10 s390x

Fixes

• BZ - 2445345 - CVE-2026-27137 crypto/x509: Incorrect enforcement of email constraints in crypto/x509
• RHEL-135848 - [Azure][RHEL-10][yggd]failed to publish message: not Connected
• RHEL-166873 - Set the MQTT LastWill message each time the client connects to the broker

CVEs

• CVE-2026-27137

References

• https://access.redhat.com/security/updates/classification/#important
• https://docs.redhat.com/en/documentation/red_hat_enterprise_linux/10/html/10.3_release_notes/index