ALAS2023-2026-2008

References: CVE-2026-42533  CVE-2026-56434  CVE-2026-60005 
FAQs regarding Amazon Linux ALAS/CVE Severity

Issue Overview:

A vulnerability exists in NGINX Plus and NGINX Open Source when a map directive uses regex matching and a string expression references the map's regex capture variables before referencing the map output variable. Alternatively, the same result could be achieved by using a non-cacheable variable in a string expression under certain conditions. An unauthenticated attacker along with conditions beyond their control can exploit this vulnerability by sending crafted HTTP requests. This may cause a heap buffer overflow 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.

Impact:
This vulnerability may allow remote attackers to cause a denial-of-service (DoS) on the NGINX system or to possibly trigger a code execution. There is no control plane exposure; this is a data plane issue only.

Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated. (CVE-2026-42533)

NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_ssi_module module. This vulnerability may exist when the Server-Side Includes (SSI), proxy_pass, and proxy_buffering off directives are configured. With this configuration, an unauthenticated attacker with man-in-the-middle (MITM) ability to control responses from an upstream server may be able to cause a use-after-free in the NGINX worker process. This issue may lead to limited modification of memory or a restart of the NGINX worker process.

Impact:
This vulnerability may allow remote attackers to have limited control to modify memory contents or restart the NGINX worker process. There is no control plane exposure; this is a data plane issue only.

Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated. (CVE-2026-56434)

NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_slice_module module. When the slice directive and unnamed regex captures are configured or when a background cache update happens, unauthenticated attackers can send requests that may cause uninitialized memory access in the NGINX worker process, leading to limited disclosure of memory or a restart.

Impact:
This vulnerability may allow remote, unauthenticated attackers to have limited control to disclose memory contents or restart the NGINX worker process. There is no control plane exposure; this is a data plane issue only.
Note: The ngx_http_slice_module module is not enabled by default; it's enabled with the --with-http_slice_module configuration parameter.

Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated. (CVE-2026-60005)

Issue Correction:
Run dnf update nginx --releasever 2023.12.20260803 or dnf update --advisory ALAS2023-2026-2008 --releasever 2023.12.20260803 to update your system.
More information on how to update your system can be found on this page: Amazon Linux 2023 documentation

New Packages:

aarch64:
    nginx-mod-http-perl-debuginfo-1.30.4-1.amzn2023.0.1.aarch64
    nginx-mod-mail-debuginfo-1.30.4-1.amzn2023.0.1.aarch64
    nginx-core-1.30.4-1.amzn2023.0.1.aarch64
    nginx-debuginfo-1.30.4-1.amzn2023.0.1.aarch64
    nginx-core-debuginfo-1.30.4-1.amzn2023.0.1.aarch64
    nginx-mod-stream-1.30.4-1.amzn2023.0.1.aarch64
    nginx-mod-devel-1.30.4-1.amzn2023.0.1.aarch64
    nginx-mod-stream-debuginfo-1.30.4-1.amzn2023.0.1.aarch64
    nginx-1.30.4-1.amzn2023.0.1.aarch64
    nginx-mod-http-image-filter-1.30.4-1.amzn2023.0.1.aarch64
    nginx-mod-http-xslt-filter-1.30.4-1.amzn2023.0.1.aarch64
    nginx-debugsource-1.30.4-1.amzn2023.0.1.aarch64
    nginx-mod-mail-1.30.4-1.amzn2023.0.1.aarch64
    nginx-mod-http-perl-1.30.4-1.amzn2023.0.1.aarch64
    nginx-mod-http-xslt-filter-debuginfo-1.30.4-1.amzn2023.0.1.aarch64
    nginx-mod-http-image-filter-debuginfo-1.30.4-1.amzn2023.0.1.aarch64

noarch:
    nginx-all-modules-1.30.4-1.amzn2023.0.1.noarch
    nginx-filesystem-1.30.4-1.amzn2023.0.1.noarch

src:
    nginx-1.30.4-1.amzn2023.0.1.src

x86_64:
    nginx-mod-stream-debuginfo-1.30.4-1.amzn2023.0.1.x86_64
    nginx-mod-http-xslt-filter-debuginfo-1.30.4-1.amzn2023.0.1.x86_64
    nginx-mod-mail-debuginfo-1.30.4-1.amzn2023.0.1.x86_64
    nginx-mod-http-image-filter-1.30.4-1.amzn2023.0.1.x86_64
    nginx-mod-stream-1.30.4-1.amzn2023.0.1.x86_64
    nginx-core-debuginfo-1.30.4-1.amzn2023.0.1.x86_64
    nginx-debugsource-1.30.4-1.amzn2023.0.1.x86_64
    nginx-mod-http-image-filter-debuginfo-1.30.4-1.amzn2023.0.1.x86_64
    nginx-mod-devel-1.30.4-1.amzn2023.0.1.x86_64
    nginx-mod-http-xslt-filter-1.30.4-1.amzn2023.0.1.x86_64
    nginx-debuginfo-1.30.4-1.amzn2023.0.1.x86_64
    nginx-mod-http-perl-1.30.4-1.amzn2023.0.1.x86_64
    nginx-mod-http-perl-debuginfo-1.30.4-1.amzn2023.0.1.x86_64
    nginx-mod-mail-1.30.4-1.amzn2023.0.1.x86_64
    nginx-1.30.4-1.amzn2023.0.1.x86_64
    nginx-core-1.30.4-1.amzn2023.0.1.x86_64