Issued at: 2026-09-10
Updated at: 2026-09-10
Advisory content derived from Red Hat RHSA-2026:65886, © Red Hat, Inc., used under CC BY 4.0, with modifications.
Synopsis
Important: image-builder security update
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: Go crypto/x509: Denial of Service via inefficient certificate chain validation (CVE-2026-32281)
* crypto/x509: crypto/tls: golang: Go: Denial of Service vulnerability in certificate chain building (CVE-2026-32280)
* net/mail: golang: net/mail: Denial of Service via pathological email address parsing (CVE-2026-42499)
* net/mail: golang: Go net/mail: Denial of Service via crafted email inputs (CVE-2026-39820)
* net: golang: Go net package: Denial of Service via long CNAME response in LookupCNAME (CVE-2026-33811)
* golang.org/x/net/idna: golang: net/http: golang.org/x/net/idna: Privilege escalation via incorrect Punycode label processing (CVE-2026-39821)
* mime: golang: Golang MIME: Denial of Service via maliciously-crafted MIME header (CVE-2026-42504)
* encoding/asn1: golang: Go encoding/asn1: Denial of Service via excessive recursion in Unmarshal (CVE-2026-33818)
* net/url: golang: golang net/url: Denial of Service from quadratic complexity in path resolution (CVE-2026-56860)
* net/http: golang: Go net/http: Unencrypted HTTP/2 connections vulnerable to Denial of Service (CVE-2026-56853)
* html/template: golang: Go html/template: Cross-Site Scripting via pathological input (CVE-2026-56858)
* crypto/tls: golang: Golang crypto/tls: Denial of Service via indefinite KeyUpdate messages (CVE-2026-56862)
* encoding/xml: golang: Go: Denial of Service via XML decoding recursion depth issue (CVE-2026-56859)
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.