Resolves: RHEL-176226 - nginx: NGINX: Arbitrary

Code Execution Vulnerability (CVE-2026-42945)

0012-Rewrite-fixed-escaping-and-possible-buffer-overrun.patch

@@ -0,0 +1,42 @@
+From d7c5b781bd24e0a1b955ee95d69e75b82f16ea0a Mon Sep 17 00:00:00 2001
+From: Roman Arutyunyan <arut@nginx.com>
+Date: Wed, 22 Apr 2026 09:39:31 +0400
+Subject: [PATCH] Rewrite: fixed escaping and possible buffer overrun
+
+The following code resulted in incorrect escaping of $1 and possible
+segfault:
+
+    location / {
+        rewrite ^(.*) /new?c=1;
+        set $myvar $1;
+        return 200 $myvar;
+    }
+
+If there were arguments in a rewrite's replacement string, the is_args flag
+was set and incorrectly never cleared.  This resulted in escaping applied
+to any captures evaluated afterwards in set or if.  Additionally buffer was
+allocated by ngx_http_script_complex_value_code() without escaping expected,
+thus this also resulted in buffer overrun and possible segfault.
+
+A similar issue was fixed in 74d939974d43.
+
+Reported by Leo Lin.
+---
+ src/http/ngx_http_script.c | 1 +
+ 1 file changed, 1 insertion(+)
+
+diff --git a/src/http/ngx_http_script.c b/src/http/ngx_http_script.c
+index a2b9f1b..2ea6113 100644
+--- a/src/http/ngx_http_script.c
++++ b/src/http/ngx_http_script.c
+@@ -1202,6 +1202,7 @@ ngx_http_script_regex_end_code(ngx_http_script_engine_t *e)
+ 
+     r = e->request;
+ 
++    e->is_args = 0;
+     e->quote = 0;
+ 
+     ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
+-- 
+2.44.0
+

nginx.spec

@@ -133,7 +133,11 @@ Patch9:            0010-Mail-fixed-clearing-s-passwd-in-auth-http-requests.patch
 
 # https://redhat.atlassian.net/browse/RHEL-157876
 # upstream patch - https://github.com/nginx/nginx/commit/7725c372c2f
-Patch10:            0011-Mp4-avoid-zero-size-buffers-in-output.patch
+Patch10:           0011-Mp4-avoid-zero-size-buffers-in-output.patch
+
+# https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2026-42945
+# upstream patch - https://github.com/nginx/nginx/commit/524977e7
+Patch11:           0012-Rewrite-fixed-escaping-and-possible-buffer-overrun.patch
 
 BuildRequires:     make
 BuildRequires:     gcc