RHSA-2026:3840 - Security Advisory

Topic

An update for image-builder 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

A local binary for building customized OS artifacts such as VM images and OSTree commits. Uses osbuild under the hood.

Security Fix(es):

• crypto/x509: golang: Denial of Service due to excessive resource consumption via crafted certificate (CVE-2025-61729)
• golang: net/url: Memory exhaustion in query parameter parsing in net/url (CVE-2025-61726)
• crypto/tls: Unexpected session resumption in crypto/tls (CVE-2025-68121)

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.

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

Fixes

• BZ - 2418462 - CVE-2025-61729 crypto/x509: golang: Denial of Service due to excessive resource consumption via crafted certificate
• BZ - 2434432 - CVE-2025-61726 golang: net/url: Memory exhaustion in query parameter parsing in net/url
• BZ - 2437111 - CVE-2025-68121 crypto/tls: Unexpected session resumption in crypto/tls

CVEs

• CVE-2025-61726
• CVE-2025-61729
• CVE-2025-68121

References

• https://access.redhat.com/security/updates/classification/#important