RHSA-2026:28038 - Security Advisory

Topic

An update for gvisor-tap-vsock is now available for Red Hat Enterprise Linux 9.6 Extended Update Support.

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 replacement for libslirp and VPNKit, written in pure Go. It is based on the network stack of gVisor. Compared to libslirp, gvisor-tap-vsock brings a configurable DNS server and dynamic port forwarding.

Security Fix(es):

• crypto/x509: Incorrect enforcement of email constraints in crypto/x509 (CVE-2026-27137)
• golang: internal/syscall/unix: Root.Chmod can follow symlinks out of the root (CVE-2026-32282)
• 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)

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 - Extended Update Support 9.6 x86_64
• Red Hat Enterprise Linux Server - AUS 9.6 x86_64
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 9.6 s390x
• Red Hat Enterprise Linux for Power, little endian - Extended Update Support 9.6 ppc64le
• Red Hat Enterprise Linux for ARM 64 - Extended Update Support 9.6 aarch64
• Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions 9.6 ppc64le
• Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 9.6 x86_64
• Red Hat Enterprise Linux for ARM 64 - 4 years of updates 9.6 aarch64
• Red Hat Enterprise Linux for IBM z Systems - 4 years of updates 9.6 s390x
• Red Hat Enterprise Linux for x86_64 - Extended Life Cycle 9.6 x86_64
• Red Hat Enterprise Linux for ARM 64 - Extended Life Cycle 9.6 aarch64
• Red Hat Enterprise Linux for Power, little endian - Extended Life Cycle 9.6 ppc64le
• Red Hat Enterprise Linux for IBM z Systems - Extended Life Cycle 9.6 s390x

Fixes

• BZ - 2445345 - CVE-2026-27137 crypto/x509: Incorrect enforcement of email constraints in crypto/x509
• BZ - 2456336 - CVE-2026-32282 golang: internal/syscall/unix: Root.Chmod can follow symlinks out of the root
• 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

CVEs

• CVE-2026-27137
• CVE-2026-32280
• CVE-2026-32282
• CVE-2026-32283

References

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