Heap-based Buffer Overflow Affecting nginx-mod-stream package, versions <2:1.26.3-2.0.1.el10_1.2


Severity

Recommended
critical

Based on Oracle Linux security rating.

Threat Intelligence

Exploit Maturity
Proof of Concept
EPSS
0.9% (76th percentile)

Do your applications use this vulnerable package?

In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.

Test your applications

Snyk Learn

Learn about Heap-based Buffer Overflow vulnerabilities in an interactive lesson.

Start learning
  • Snyk IDSNYK-ORACLE10-NGINXMODSTREAM-16761226
  • published19 May 2026
  • disclosed13 May 2026

Introduced: 13 May 2026

NewCVE-2026-42945  (opens in a new tab)
CWE-122  (opens in a new tab)

How to fix?

Upgrade Oracle:10 nginx-mod-stream to version 2:1.26.3-2.0.1.el10_1.2 or higher.
This issue was patched in ELSA-2026-18063.

NVD Description

Note: Versions mentioned in the description apply only to the upstream nginx-mod-stream package and not the nginx-mod-stream package as distributed by Oracle. See How to fix? for Oracle:10 relevant fixed versions and status.

NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_rewrite_module module. This vulnerability exists when the rewrite directive is followed by a rewrite, if, or set directive and an unnamed Perl-Compatible Regular Expression (PCRE) capture (for example, $1, $2) with a replacement string that includes a question mark (?). An unauthenticated attacker along with conditions beyond its 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.  Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

CVSS Base Scores

version 3.1