CVE intelligence and bounded remediation

CVE-2026-42530 — NGINX Open Source has a vulnerability in the ngx_http_v3_module module

Critical CVSS 9.2

NGINX Open Source has a vulnerability in the ngx_http_v3_module module. When NGINX Open Source is configured to use the HTTP/3 QUIC module, a remote unauthenticated attacker along with conditions beyond their control can use a specially crafted HTTP/3 session to reopen a QPACK encoder stream. This may cause a Use-after-Free in the NGINX worker process leading to a restart. Additionally, attackers can execute code on systems with Address Space Layout Randomization (ASLR) disabled or when the attacker can bypass ASLR. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

Severity
Critical
CVSS
9.2 (4.0)
Published
2026-06-17
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-416

Affected products

  • f5 / nginx_gateway_fabric
  • f5 / nginx_ingress_controller
  • f5 / nginx_ingress_controller / 4.0.0
  • f5 / nginx_ingress_controller / 4.0.1
  • f5 / nginx_instance_manager
  • f5 / nginx_open_source

Showing 6 representative product identities from 8 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Use-after-free, double free, and expired resource use

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Trace ownership, references, callbacks, asynchronous tasks, and teardown paths around the affected object or resource.
  • Identify reachable inputs and timing or state transitions that can release the object while references remain.
  • Confirm affected builds, allocators, feature flags, architectures, and process privileges.

Remediate safely

  • Apply the maintained ownership or lifetime fix and rebuild all artifacts containing the affected native code.
  • Use explicit ownership, safe reference management, cancellation and join semantics, and idempotent teardown.
  • Add deterministic lifetime tests plus isolated sanitizer and concurrency coverage for shutdown and error paths.

Authoritative sources

Complete CVE record and remediation plan

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