Is CVE-2026-42530 actively exploited?

No active exploitation of CVE-2026-42530 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2026-42530 be exploited remotely?

Yes. CVE-2026-42530 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2026-42530?

CVE-2026-42530 has a CVSS score of 8.1 (HIGH).

HOME VULNERABILITIESCVE-2026-42530

HIGH

CVE-2026-42530

CWE-416Published: June 17, 2026· Updated: Jun 18, 2026

8.1

CVSS v3.1

Official 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.

NVD Source

Technical Analysis

CVE-2026-42530 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 8.1.

From a weakness classification perspective (CWE-416): Use-after-free vulnerabilities involve accessing memory after it has been freed, often enabling arbitrary code execution.

CVSS v3.1 Vector Breakdown

Exploitability

Attack VectorNetwork

Attack ComplexityHigh

Privileges Req.None

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected Vendors & Products

Mentioned vendors (from description):

NGINX

CPE data not yet available in NVD for this CVE.

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time

Exploit-DB

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GitHub PoC Search

Community PoC repositories

Rapid7 / Metasploit

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PacketStorm

Security advisories & exploits

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News & Research Mentioning CVE-2026-42530

F5 Patches Two Critical NGINX Open Source Flaws Enabling Remote Code Execution

The Hacker News· Jun 18, 2026

F5 has released security updates to address two critical security flaws in NGINX Open Source that could be exploited to achieve code execution on affected systems. The vulnerabilities are listed below - CVE-2026-42530 (CVSS v4 score: 9.2) - A use-after-free vulnerability in the ngx_http_v3_module that could be triggered by a remote unauthenticated attacker when NGINX Open Source is [xlite_meta score:50 src:The Hacker News xlite_fp:4a308d756777d07753fdd27f3e8df4cb9d61b5765511af55b16a7fbd751fc87a]