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.

According to its Server response header, the installed version of nginx is prior to 1.30.3 or 1.31.x prior to 1.31.2. It is, therefore, affected by the following issues :

- A Use-After-Free in the ngx_http_v3_module module allows a remote unauthenticated attacker to send a specially crafted HTTP/3 session that reopens a QPACK encoder stream, causing a worker process restart or, on systems with ASLR disabled, arbitrary code execution. (CVE-2026-42530)

- A heap-based buffer overflow in the ngx_http_proxy_v2_module and ngx_http_grpc_module modules allows a remote unauthenticated attacker to send large headers during upstream request creation when proxy_http_version 2 or grpc_pass is used with ignore_invalid_headers off and large_client_header_buffers configured above 2 megabytes, causing a worker process restart or, on systems with ASLR disabled, arbitrary code execution. (CVE-2026-42055)

- A heap buffer over-read (CWE-125) in the ngx_http_charset_module module allows a remote unauthenticated attacker to cause limited memory disclosure or a worker process restart when content is served or proxied through a location block configured with both source_charset utf-8 and a charset conversion directive. (CVE-2026-48142)

Note that the scanner has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote Fedora 43 host has packages installed that are affected by multiple vulnerabilities as referenced in the FEDORA-2026-9d7328702e advisory.

    nginx-mod-headers-more:

    - Rebuild for 1.30.3

    nginx-mod-brotli:

    - Rebuild for 1.30.3

    nginx-mod-vts:

    - Rebuild for 1.30.3

    nginx-mod-modsecurity:

    - Rebuild for 1.30.3

    nginx-mod-fancyindex:

    - Rebuild for 1.30.3

    nginx-mod-naxsi:

    - Rebuild for 1.30.3

    nginx:

    - update to 1.30.3
    - fixes CVE-2026-42055, CVE-2026-42530 and CVE-2026-48142




Tenable has extracted the preceding description block directly from the Fedora security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote Fedora 44 host has packages installed that are affected by multiple vulnerabilities as referenced in the FEDORA-2026-b8e751787c advisory.

    nginx-mod-brotli:

    - Rebuild for 1.30.3

    nginx-mod-fancyindex:

    - Rebuild for 1.30.3

    nginx-mod-vts:

    - Rebuild for 1.30.3

    nginx-mod-modsecurity:

    - Rebuild for 1.30.3

    nginx-mod-headers-more:

    - Rebuild for 1.30.3

    nginx-mod-naxsi:

    - Rebuild for 1.30.3

    nginx-mod-js-challenge:

    - Rebuild for 1.30.3

    nginx:

    - update to 1.30.3
    - fixes CVE-2026-42055, CVE-2026-42530 and CVE-2026-48142




Tenable has extracted the preceding description block directly from the Fedora security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The version of FreeBSD installed on the remote host is prior to tested version. It is, therefore, affected by multiple vulnerabilities as referenced in the 08b0c0f6-6a85-11f1-b8e5-3497f65b111b advisory.

    The nginx developers report:

           A use-after-free vulnerability when using HTTP/3 and processing a            specially crafted QUIC session may allow memory corruption or a            segmentation fault in a worker process (CVE-2026-42530).


           A heap memory buffer overflow vulnerability when using the            ignore_invalid_headers off; and large_client_header_buffers            directives with large configured values while proxying a specially            crafted request to an HTTP/2 or gRPC backend may allow memory            corruption or a segmentation fault in a worker process            (CVE-2026-42055).


           A heap memory buffer overread vulnerability while handling a            specially crafted response with decoding from UTF-8 via the            charset_map directive may allow limited disclosure of worker            process memory or a segmentation fault in a worker process            (CVE-2026-48142).


Tenable has extracted the preceding description block directly from the FreeBSD security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

CVE does not affect Ubuntu operating systems.

The remote Fedora 45 host has packages installed that are affected by multiple vulnerabilities as referenced in the FEDORA-2026-e212182e6e advisory.

    nginx-mod-brotli:

    - Rebuild for 1.30.3

    nginx-mod-fancyindex:

    - Rebuild for 1.30.3

    nginx-mod-modsecurity:

    - Rebuild for 1.30.3

    nginx-mod-headers-more:

    - Rebuild for 1.30.3

    nginx-mod-naxsi:

    - Rebuild for 1.30.3

    nginx-mod-js-challenge:

    - Rebuild for 1.30.3

    nginx-mod-vts:

    - Rebuild for 1.30.3

    nginx:

    - update to 1.30.3
    - fixes CVE-2026-42055, CVE-2026-42530 and CVE-2026-48142



Tenable has extracted the preceding description block directly from the Fedora security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The installed version of nginx is 1.31.x prior to 1.31.2. It is, therefore, affected by the following vulnerability:

  - 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. (CVE-2026-42530)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

ID	Name	Product	Family	Severity
115285	Nginx < 1.30.3 Multiple Vulnerabilities	Web App Scanning	Component Vulnerability	critical
115284	Nginx 1.31.x < 1.31.2 Multiple Vulnerabilities	Web App Scanning	Component Vulnerability	critical
323138	Fedora 43 : nginx / nginx-mod-brotli / nginx-mod-fancyindex / etc (2026-9d7328702e)	Nessus	Fedora Local Security Checks	critical
323136	Fedora 44 : nginx / nginx-mod-brotli / nginx-mod-fancyindex / etc (2026-b8e751787c)	Nessus	Fedora Local Security Checks	critical
321716	FreeBSD : nginx -- multiple vulnerabilities (08b0c0f6-6a85-11f1-b8e5-3497f65b111b)	Nessus	FreeBSD Local Security Checks	critical
321621	Linux Distros Unpatched Vulnerability : CVE-2026-42530 (deprecated)	Nessus	Misc.	critical
321546	Fedora 45 : nginx / nginx-mod-brotli / nginx-mod-fancyindex / etc (2026-e212182e6e)	Nessus	Fedora Local Security Checks	critical
321538	nginx 1.31.x < 1.31.2 Use-After-Free Vulnerability	Nessus	Web Servers	critical

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CVE-2026-42530

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