High 8.1Published Jun 17, 2026

CVE-2026-42530NGINX Open-Source ngx_http_v3_module vulnerability

Updated under an hour ago (Oct 26, 2026, 7:20 PM ET)

Does this affect you?

It affects F5 NGINX Open Source and 6 other products. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

Do this next

Start free and add your stack

Free account, 1 product

Every CVE for F5 NGINX Open Source

Exploited in the last 30 days

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.

CVSS: 8.1 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness (CWE): CWE-416
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: f5
NVD analysis: Modified
Record last updated: Jul 16, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

F5 NGINX Open Source f5:nginx_open_source (from the name)	from 1.31.0 before 1.31.2	CNA record
Red Hat Red Hat Hardened Images redhat:hummingbird	from 1.30.2-1.hum1 not affected	CISA ADP
Red Hat Red Hat Enterprise Linux 10 redhat:enterprise_linux	10	CISA ADP
Red Hat Red Hat Lightspeed proxy 1 redhat:insights_proxy	1	CISA ADP
f5 nginx_gateway_fabric f5:nginx_gateway_fabric	from 1.3.0 through 1.6.2; from 2.0.0 before 2.6.4	NVD
f5 nginx_ingress_controller f5:nginx_ingress_controller	from 3.5.0 through 3.7.2; from 5.0.0 before 5.5.1; 4.0.0; 4.0.1	NVD
f5 nginx_instance_manager f5:nginx_instance_manager	from 2.17.0 through 2.22.0	NVD
f5 nginx_open_source f5:nginx_open_source	from 1.31.0 before 1.31.2	NVD

References

References

https://my.f5.com/manage/s/article/K000161616	vendor-advisory
https://access.redhat.com/errata/RHSA-2026:20351
https://access.redhat.com/security/cve/CVE-2026-42530	third-party-advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2489872	third-party-advisory
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-42530.json	third-party-advisory

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.