Out-of-bounds Write Affecting nginx package, versions <1.21.5-150400.3.25.1


Severity

Recommended
0.0
high
0
10

Based on SUSE Linux Enterprise Server security rating.

Threat Intelligence

EPSS
4.04% (90th percentile)

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  • Snyk IDSNYK-SLES154-NGINX-18516352
  • published4 Aug 2026
  • disclosed3 Aug 2026

Introduced: 3 Aug 2026

NewCVE-2026-42055  (opens in a new tab)
CWE-787  (opens in a new tab)

How to fix?

Upgrade SLES:15.4 nginx to version 1.21.5-150400.3.25.1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream nginx package and not the nginx package as distributed by SLES. See How to fix? for SLES:15.4 relevant fixed versions and status.

NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_proxy_v2_module and ngx_http_grpc_module modules. This vulnerability exists when the proxy_http_version to 2 or grpc_pass directives are used to proxy HTTP/2 traffic, the ignore_invalid_headers directive is set to off, and the large_client_header_buffers directive size is larger than 2 megabytes. A remote, unauthenticated attacker, along with conditions beyond their control, could send large headers while creating an upstream request. This may cause a heap-based 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.

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

CVSS Base Scores

version 3.1