Heap-based Buffer Overflow Affecting nginx-core-debuginfo package, versions <2:1.26.3-9.module+el9.8.0+40194+40adfc1b


Severity

Recommended
critical

Based on Rocky Linux security rating.

Threat Intelligence

Exploit Maturity
Proof of Concept
EPSS
0.42% (63rd 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-ROCKY9-NGINXCOREDEBUGINFO-16794019
  • published22 May 2026
  • disclosed13 May 2026

Introduced: 13 May 2026

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

How to fix?

Upgrade Rocky-Linux:9 nginx-core-debuginfo to version 2:1.26.3-9.module+el9.8.0+40194+40adfc1b or higher.
This issue was patched in RLSA-2026:19372.

NVD Description

Note: Versions mentioned in the description apply only to the upstream nginx-core-debuginfo package and not the nginx-core-debuginfo package as distributed by Rocky-Linux. See How to fix? for Rocky-Linux:9 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