nginx: fix CVE-2026-15176

This patch applies the upstream fix as referenced in [2],
using the commit shown in [1].

[1] https://github.com/nginx/nginx/commit/ce1da78900b07e72f37a25f55e6606220ac45902
[2] https://ubuntu.com/security/CVE-2026-15176

Signed-off-by: Hetvi Thakar <hthakar@cisco.com>
Signed-off-by: Anuj Mittal <anuj.mittal@oss.qualcomm.com>

meta-webserver/recipes-httpd/nginx/files/CVE-2026-15176.patch

@@ -0,0 +1,54 @@
+From ce1da78900b07e72f37a25f55e6606220ac45902 Mon Sep 17 00:00:00 2001
+From: Roman Arutyunyan <arut@nginx.com>
+Date: Fri, 10 Jul 2026 20:10:12 +0400
+Subject: [PATCH] Avoid post-rewrite URI to path mapping with alias
+
+Previously, after a "rewrite" had changed the URI, and before a new
+location was chosen, the new URI might not match the current location
+prefix.  This becomes a problem when the location uses "alias", which
+is why normally such inconsistency is detected by checking the
+r->valid_location flag.  Meanwhile this flag only handles the
+inconsistency when using the "break" directive or parameter.  However
+in absence of those, there's still an inconsistency window from URI
+change up until the end of the current set of rewrite directives.
+URI to path mapping within this window might result in a buffer
+overflow if location's prefix was longer than the rewritten URI.
+
+The following example resulted in a buffer overflow with the request
+"/foo/1":
+
+location /foo/ {
+    alias /bar/;
+    rewrite ^/foo/.*$ /x;
+    return 200 $request_filename;
+}
+
+Alternatively, $request_filename might be used in access log format,
+"set", "if", "add_header", etc.
+
+The fix is to reject URI mapping in ngx_http_map_uri_to_path() if the
+r->uri_changed flag is set.
+
+CVE: CVE-2026-15176
+Upstream-Status: Backport [https://github.com/nginx/nginx/commit/ce1da78900b07e72f37a25f55e6606220ac45902]
+
+Signed-off-by: Hetvi Thakar <hthakar@cisco.com>
+---
+ src/http/ngx_http_core_module.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/src/http/ngx_http_core_module.c b/src/http/ngx_http_core_module.c
+index a5f4597294..385b84e1b3 100644
+--- a/src/http/ngx_http_core_module.c
++++ b/src/http/ngx_http_core_module.c
+@@ -1936,7 +1936,7 @@ ngx_http_map_uri_to_path(ngx_http_request_t *r, ngx_str_t *path,
+ 
+     alias = clcf->alias;
+ 
+-    if (alias && !r->valid_location) {
++    if (alias && (!r->valid_location || r->uri_changed)) {
+         ngx_log_error(NGX_LOG_ALERT, r->connection->log, 0,
+                       "\"alias\" cannot be used in location \"%V\" "
+                       "where URI was rewritten", &clcf->name);
+-- 
+2.35.6

meta-webserver/recipes-httpd/nginx/nginx_1.28.3.bb

@@ -17,6 +17,7 @@ SRC_URI:append = " \
     file://CVE-2026-56434.patch \
     file://CVE-2026-95101.patch \
     file://CVE-2026-97629.patch \
+    file://CVE-2026-15176.patch \
 "
 
 LIC_FILES_CHKSUM = "file://LICENSE;md5=3dc49537b08b14c8b66ad247bb4c4593"

meta-webserver/recipes-httpd/nginx/nginx_1.29.7.bb

@@ -17,6 +17,7 @@ SRC_URI:append = " \
     file://CVE-2026-56434.patch \
     file://CVE-2026-95101.patch \
     file://CVE-2026-97629.patch \
+    file://CVE-2026-15176.patch \
 "
 
 # 1.28.x branch is the current stable branch, the recommended default