RHSA-2026:66605HighCVSS 7.5

Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update

Published
September 11, 2026
Last Modified
September 11, 2026

🔗 CVE IDs covered (4)

CVE-2026-19534 →CVE-2026-84961 →CVE-2026-85024 →CVE-2026-18540 →

📋 Description

CVE-2026-18540 — undici: undici: HTTP response splitting via retry interceptor CVE-2026-19534 — undici: undici: Denial of Service via unrequested WebSocket subprotocol CVE-2026-84961 — undici: undici: TLS certificate validation bypass in BalancedPool via dropped connect options CVE-2026-85024 — undici: undici: Denial of Service via unhandled error in WebSocket permessage-deflate decompression

🎯 Affected products5

  • Red Hat Hardened Images
  • nodejs26-main@aarch64 as a component of Red Hat Hardened Images
  • nodejs26-main@noarch as a component of Red Hat Hardened Images
  • nodejs26-main@src as a component of Red Hat Hardened Images
  • nodejs26-main@x86_64 as a component of Red Hat Hardened Images

✅ Remediation

For details on how to apply this update, which includes the changes described in this advisory, refer to: https://images.redhat.com/ Workaround: Disable interceptors.retry() for untrusted upstreams, or set maxRetries: 0 on the retry interceptor configuration. Alternatively, remove or recalculate the Content-Length header before forwarding a response body assembled by undici to downstream HTTP/1.1 peers. 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: Applications that do not use BalancedPool, or that use it without a custom function-valued connect/tls option, are not affected and require no action. As a workaround until packages are updated, avoid using BalancedPool for any connection that relies on custom TLS certificate validation (e.g. certificate pinning); use Client, Pool, or Agent instead, which are unaffected. The permanent fix is upgrading undici to 7.29.1 or later (7.x line) or 8.10.2 or later (8.x line).

🔗 References (8)