RHSA-2026:96076HighCVSS 8.8

Red Hat Security Advisory: osbuild-composer security update

Published
November 9, 2026
Last Modified
November 14, 2026

🔗 CVE IDs covered (17)

CVE-2025-68121 →CVE-2026-39821 →CVE-2026-56853 →CVE-2026-56860 →CVE-2026-33818 →CVE-2026-97031 →CVE-2026-32280 →CVE-2026-32281 →CVE-2026-55677 →CVE-2026-78667 →CVE-2026-78669 →CVE-2026-33810 →CVE-2026-42504 →CVE-2026-56858 →CVE-2026-56859 →CVE-2026-56862 →CVE-2026-94440 →

📋 Description

CVE-2025-68121 — crypto/tls: crypto/tls: Incorrect certificate validation during TLS session resumption CVE-2026-32280 — crypto/x509: crypto/tls: golang: Go: Denial of Service vulnerability in certificate chain building CVE-2026-32281 — crypto/x509: golang: Go crypto/x509: Denial of Service via inefficient certificate chain validation CVE-2026-33810 — crypto/x509: golang: Go crypto/x509: Certificate validation bypass due to incorrect DNS constraint application CVE-2026-33818 — encoding/asn1: golang: Go encoding/asn1: Denial of Service via excessive recursion in Unmarshal CVE-2026-39821 — golang.org/x/net/idna: golang: net/http: golang.org/x/net/idna: Privilege escalation via incorrect Punycode label processing CVE-2026-42504 — mime: golang: Golang MIME: Denial of Service via maliciously-crafted MIME header CVE-2026-55677 — github.com/labstack/echo: Echo: Unauthorized Information Disclosure via URL Path Decoding Discrepancy CVE-2026-56853 — net/http: golang: Go net/http: Unencrypted HTTP/2 connections vulnerable to Denial of Service CVE-2026-56858 — html/template: golang: Go html/template: Cross-Site Scripting via pathological input CVE-2026-56859 — encoding/xml: golang: Go: Denial of Service via XML decoding recursion depth issue CVE-2026-56860 — net/url: golang: golang net/url: Denial of Service from quadratic complexity in path resolution CVE-2026-56862 — crypto/tls: golang: Golang crypto/tls: Denial of Service via indefinite KeyUpdate messages CVE-2026-78667 — net/http: golang: golang: Denial of Service via crafted HTTP Range headers CVE-2026-78669 — net/http: net/http/internal/http2: golang.org/x/net/http2: net/http: Denial of Service via excessive HTTP/2 SETTINGS frames CVE-2026-94440 — net/textproto: mime/multipart: golang: golang: Denial of Service via memory limit bypass in multipart form parsing CVE-2026-97031 — crypto/tls: golang: crypto/tls: Denial of Service via multiple ECH outer extension references

🎯 Affected products20

  • Red Hat Enterprise Linux AppStream AUS (v.8.4)
  • Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4)
  • osbuild-composer-0:28.7-7.el8_4.src as a component of Red Hat Enterprise Linux AppStream AUS (v.8.4)
  • osbuild-composer-0:28.7-7.el8_4.src as a component of Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4)
  • osbuild-composer-0:28.7-7.el8_4.x86_64 as a component of Red Hat Enterprise Linux AppStream AUS (v.8.4)
  • osbuild-composer-0:28.7-7.el8_4.x86_64 as a component of Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4)
  • osbuild-composer-core-0:28.7-7.el8_4.x86_64 as a component of Red Hat Enterprise Linux AppStream AUS (v.8.4)
  • osbuild-composer-core-0:28.7-7.el8_4.x86_64 as a component of Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4)
  • osbuild-composer-core-debuginfo-0:28.7-7.el8_4.x86_64 as a component of Red Hat Enterprise Linux AppStream AUS (v.8.4)
  • osbuild-composer-core-debuginfo-0:28.7-7.el8_4.x86_64 as a component of Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4)
  • osbuild-composer-debuginfo-0:28.7-7.el8_4.x86_64 as a component of Red Hat Enterprise Linux AppStream AUS (v.8.4)
  • osbuild-composer-debuginfo-0:28.7-7.el8_4.x86_64 as a component of Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4)
  • osbuild-composer-debugsource-0:28.7-7.el8_4.x86_64 as a component of Red Hat Enterprise Linux AppStream AUS (v.8.4)
  • osbuild-composer-debugsource-0:28.7-7.el8_4.x86_64 as a component of Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4)
  • osbuild-composer-tests-debuginfo-0:28.7-7.el8_4.x86_64 as a component of Red Hat Enterprise Linux AppStream AUS (v.8.4)
  • osbuild-composer-tests-debuginfo-0:28.7-7.el8_4.x86_64 as a component of Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4)
  • osbuild-composer-worker-0:28.7-7.el8_4.x86_64 as a component of Red Hat Enterprise Linux AppStream AUS (v.8.4)
  • osbuild-composer-worker-0:28.7-7.el8_4.x86_64 as a component of Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4)
  • osbuild-composer-worker-debuginfo-0:28.7-7.el8_4.x86_64 as a component of Red Hat Enterprise Linux AppStream AUS (v.8.4)
  • osbuild-composer-worker-debuginfo-0:28.7-7.el8_4.x86_64 as a component of Red Hat Enterprise Linux AppStream EUS EXTENSION (v.8.4)

✅ Remediation

For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 Workaround: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability. Workaround: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability. Workaround: Upgrade to a fixed golang.org/x/net release that includes the idna correction, via updated golang or dependent package rebuilds. Workaround: To mitigate this issue, restrict network access to services that process MIME headers from untrusted sources. Implement input validation and sanitization for all incoming data, especially MIME headers, to prevent maliciously crafted content from being processed by applications utilizing the vulnerable Golang MIME package. Workaround: In case you consume HTTP2, upgrade to a patched version of the http module. Verify: ``` go version go list -m golang.org/x/net govulncheck ./... ```

🔗 References (20)