RHSA-2026:29455 - Security Advisory

Topic

An update for buildah is now available for Red Hat Enterprise Linux 9.

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

The buildah package provides a tool for facilitating building OCI container images. Among other things, buildah enables you to: Create a working container, either from scratch or using an image as a starting point; Create an image, either from a working container or using the instructions in a Dockerfile; Build both Docker and OCI images.

Security Fix(es):

• net/url: Incorrect parsing of IPv6 host literals in net/url (CVE-2026-25679)
• crypto/x509: golang: Go crypto/x509: Denial of Service via inefficient certificate chain validation (CVE-2026-32281)
• crypto/tls: golang: Go crypto/tls: Denial of Service via multiple TLS 1.3 key update messages (CVE-2026-32283)
• crypto/x509: crypto/tls: golang: Go: Denial of Service vulnerability in certificate chain building (CVE-2026-32280)
• golang.org/x/crypto/ssh: golang.org/x/crypto/ssh: Denial of Service via crafted public key with excessive parameters (CVE-2026-39829)
• golang.org/x/crypto/ssh: golang.org/x/crypto/ssh: Denial of Service via resource leak from unsolicited SSH responses (CVE-2026-39830)

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 9 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 9.8 x86_64
• Red Hat Enterprise Linux for IBM z Systems 9 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 9.8 s390x
• Red Hat Enterprise Linux for Power, little endian 9 ppc64le
• Red Hat Enterprise Linux for Power, little endian - Extended Update Support 9.8 ppc64le
• Red Hat Enterprise Linux for ARM 64 9 aarch64
• Red Hat Enterprise Linux for ARM 64 - Extended Update Support 9.8 aarch64
• Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions 9.8 ppc64le
• Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 9.8 x86_64
• Red Hat Enterprise Linux for ARM 64 - 4 years of updates 9.8 aarch64
• Red Hat Enterprise Linux for IBM z Systems - 4 years of updates 9.8 s390x
• Red Hat Enterprise Linux for x86_64 - Extended Life Cycle 9.8 x86_64
• Red Hat Enterprise Linux for ARM 64 - Extended Life Cycle 9.8 aarch64
• Red Hat Enterprise Linux for Power, little endian - Extended Life Cycle 9.8 ppc64le
• Red Hat Enterprise Linux for IBM z Systems - Extended Life Cycle 9.8 s390x

Fixes

• BZ - 2445356 - CVE-2026-25679 net/url: Incorrect parsing of IPv6 host literals in net/url
• BZ - 2456333 - CVE-2026-32281 crypto/x509: golang: Go crypto/x509: Denial of Service via inefficient certificate chain validation
• BZ - 2456338 - CVE-2026-32283 crypto/tls: golang: Go crypto/tls: Denial of Service via multiple TLS 1.3 key update messages
• BZ - 2456339 - CVE-2026-32280 crypto/x509: crypto/tls: golang: Go: Denial of Service vulnerability in certificate chain building
• BZ - 2480681 - CVE-2026-39829 golang.org/x/crypto/ssh: golang.org/x/crypto/ssh: Denial of Service via crafted public key with excessive parameters
• BZ - 2480684 - CVE-2026-39830 golang.org/x/crypto/ssh: golang.org/x/crypto/ssh: Denial of Service via resource leak from unsolicited SSH responses

CVEs

• CVE-2026-25679
• CVE-2026-32280
• CVE-2026-32281
• CVE-2026-32283
• CVE-2026-39829
• CVE-2026-39830

References

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