NGINX Open-Source ngx_http_v3_module vulnerability
Summary
| CVE | CVE-2026-42530 |
|---|---|
| State | PUBLISHED |
| Assigner | f5 |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-06-17 15:16:50 UTC |
| Updated | 2026-07-02 20:03:41 UTC |
| Description | 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. |
Risk And Classification
Primary CVSS: v4.0 9.2 CRITICAL from [email protected]
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS: 0.032250000 probability, percentile 0.867100000 (date 2026-07-05)
Problem Types: CWE-416 | CWE-416 CWE-416 Use After Free | CWE-416 Use After Free
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | [email protected] | Secondary | 9.2 | CRITICAL | CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/C... |
| 4.0 | CNA | CVSS | 9.2 | CRITICAL | CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N |
| 3.1 | ADP | CVSS | 8.1 | HIGH | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H |
| 3.1 | [email protected] | Secondary | 8.1 | HIGH | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H |
| 3.1 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | Secondary | 8.1 | HIGH | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H |
| 3.1 | CNA | CVSS | 8.1 | HIGH | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H |
CVSS v4.0 Breakdown
CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS v3.1 Breakdown
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD Known Affected Configurations (CPE 2.3)
| Type | Vendor | Product | Version | Update | Edition | Language |
|---|---|---|---|---|---|---|
| Application | F5 | Nginx Gateway Fabric | All | All | All | All |
| Application | F5 | Nginx Gateway Fabric | All | All | All | All |
| Application | F5 | Nginx Ingress Controller | All | All | All | All |
| Application | F5 | Nginx Ingress Controller | 4.0.0 | All | All | All |
| Application | F5 | Nginx Ingress Controller | 4.0.1 | All | All | All |
| Application | F5 | Nginx Ingress Controller | All | All | All | All |
| Application | F5 | Nginx Instance Manager | All | All | All | All |
| Application | F5 | Nginx Open Source | All | All | All | All |
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | F5 | NGINX Open Source | affected 1.31.0 1.31.2 custom | Not specified |
| ADP | Red Hat | Red Hat Hardened Images | Not specified | Not specified |
| ADP | Red Hat | Red Hat Enterprise Linux 10 | Not specified | Not specified |
| ADP | Red Hat | Red Hat Enterprise Linux 8 | Not specified | Not specified |
| ADP | Red Hat | Red Hat Enterprise Linux 9 | Not specified | Not specified |
| ADP | Red Hat | Red Hat Lightspeed Proxy 1 | Not specified | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| bugzilla.redhat.com/show_bug.cgi | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | bugzilla.redhat.com | Third Party Advisory |
| my.f5.com/manage/s/article/K000161616 | [email protected] | my.f5.com | Vendor Advisory |
| access.redhat.com/security/cve/CVE-2026-42530 | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | access.redhat.com | Third Party Advisory |
| security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-42530.json | 0b0ca135-0b70-47e7-9f44-1890c2a1c46c | security.access.redhat.com | Third Party Advisory |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: "F5 acknowledges Trung Nguyen (@everping) of CyStack, Zhenpeng (Leo) Lin (depthfirst), Evan Hellman (@xintenseapple) of Trail of Bits in collaboration with OpenAI, AntAISecurityLab, and Nebula Security (@nebusecurity) for bringing this issue to our attention and following the highest standards of coordinated disclosure." (en)
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| ADP | 2026-06-17T16:02:06.547Z | Reported to Red Hat. |
| ADP | 2026-06-17T14:04:32.173Z | Made public. |
Workarounds
ADP: To mitigate this vulnerability, disable HTTP/3 by removing quic from all listen directives.