Heap-based Buffer Overflow Affecting nginx-mod-http-xslt-filter package, versions <2:1.26.3-6.el10_2.3


Severity

Recommended
critical

Based on AlmaLinux security rating.

Threat Intelligence

Exploit Maturity
Proof of Concept
EPSS
61.47% (100th percentile)

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  • Snyk IDSNYK-ALMALINUX10-NGINXMODHTTPXSLTFILTER-16770192
  • published20 May 2026
  • disclosed19 May 2026

Introduced: 19 May 2026

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

How to fix?

Upgrade AlmaLinux:10 nginx-mod-http-xslt-filter to version 2:1.26.3-6.el10_2.3 or higher.
This issue was patched in ALSA-2026:19159.

NVD Description

Note: Versions mentioned in the description apply only to the upstream nginx-mod-http-xslt-filter package and not the nginx-mod-http-xslt-filter package as distributed by AlmaLinux. See How to fix? for AlmaLinux: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