diff --git a/manifests/mod/security.pp b/manifests/mod/security.pp
index 3d00e61b27..bbcf497f11 100644
--- a/manifests/mod/security.pp
+++ b/manifests/mod/security.pp
@@ -137,7 +137,10 @@
 # @see https://github.com/SpiderLabs/ModSecurity/wiki for additional documentation.
 # @see https://coreruleset.org/docs/ for addional documentation
 #
-# @note Unsupported platforms: RedHat: 10
+# @note On RHEL/EL 10 the ModSecurity engine is provided by EPEL (enable EPEL
+#   yourself; this module does not manage it). The OWASP CRS package
+#   (`mod_security_crs`) is not available on EL10, so the class manages the
+#   engine only there and does not install or activate CRS rules.
 class apache::mod::security (
   Stdlib::Absolutepath $logroot                                = $apache::params::logroot,
   Integer $version                                             = $apache::params::modsec_version,
diff --git a/manifests/params.pp b/manifests/params.pp
index 6ca2e15703..48763db608 100644
--- a/manifests/params.pp
+++ b/manifests/params.pp
@@ -115,12 +115,23 @@
     $mellon_cache_size    = 100
     $mellon_post_directory = undef
     $modsec_version       = 1
-    $modsec_crs_package   = 'mod_security_crs'
+    # EL10 base/EPEL ships the ModSecurity engine but not the mod_security_crs
+    # package, so install the engine only and leave CRS unmanaged there.
+    $modsec_crs_package   = $facts['os']['release']['major'] ? {
+      '10'    => undef, # RedHat 10 doesn't ship mod_security_crs (CRS tracked separately)
+      default => 'mod_security_crs',
+    }
     $modsec_dir           = '/etc/httpd/modsecurity.d'
     $secpcrematchlimit = 1500
     $secpcrematchlimitrecursion = 1500
     $modsec_secruleengine = 'On'
-    if $facts['os']['family'] == 'RedHat' and versioncmp($facts['os']['release']['major'], '7') <= 0 {
+    if $facts['os']['family'] == 'RedHat' and versioncmp($facts['os']['release']['major'], '10') >= 0 {
+      # Engine-only on EL10: no CRS package, so no rules are activated. The path
+      # is kept at the EL8+ default since it is only referenced when rules are
+      # activated (none here).
+      $modsec_crs_path      = '/usr/share/mod_modsecurity_crs'
+      $modsec_default_rules = []
+    } elsif $facts['os']['family'] == 'RedHat' and versioncmp($facts['os']['release']['major'], '7') <= 0 {
       $modsec_crs_path      = '/usr/lib/modsecurity.d'
       $modsec_default_rules = [
         'base_rules/modsecurity_35_bad_robots.data',
@@ -260,12 +271,23 @@
     $mellon_cache_size    = 100
     $mellon_post_directory = undef
     $modsec_version       = 1
-    $modsec_crs_package   = 'mod_security_crs'
+    # EL10 base/EPEL ships the ModSecurity engine but not the mod_security_crs
+    # package, so install the engine only and leave CRS unmanaged there.
+    $modsec_crs_package   = $facts['os']['release']['major'] ? {
+      '10'    => undef, # RedHat 10 doesn't ship mod_security_crs (CRS tracked separately)
+      default => 'mod_security_crs',
+    }
     $modsec_dir           = '/etc/httpd/modsecurity.d'
     $secpcrematchlimit = 1500
     $secpcrematchlimitrecursion = 1500
     $modsec_secruleengine = 'On'
-    if $facts['os']['family'] == 'RedHat' and versioncmp($facts['os']['release']['major'], '7') <= 0 {
+    if $facts['os']['family'] == 'RedHat' and versioncmp($facts['os']['release']['major'], '10') >= 0 {
+      # Engine-only on EL10: no CRS package, so no rules are activated. The path
+      # is kept at the EL8+ default since it is only referenced when rules are
+      # activated (none here).
+      $modsec_crs_path      = '/usr/share/mod_modsecurity_crs'
+      $modsec_default_rules = []
+    } elsif $facts['os']['family'] == 'RedHat' and versioncmp($facts['os']['release']['major'], '7') <= 0 {
       $modsec_crs_path      = '/usr/lib/modsecurity.d'
       $modsec_default_rules = [
         'base_rules/modsecurity_35_bad_robots.data',
diff --git a/spec/classes/mod/security_spec.rb b/spec/classes/mod/security_spec.rb
index 1263777670..b9ff1a8de9 100644
--- a/spec/classes/mod/security_spec.rb
+++ b/spec/classes/mod/security_spec.rb
@@ -33,7 +33,12 @@
             )
           }
 
-          it { is_expected.to contain_package('mod_security_crs') }
+          if facts[:os]['release']['major'].to_i >= 10
+            # EL10 ships the engine via EPEL but not the mod_security_crs package.
+            it { is_expected.not_to contain_package('mod_security_crs') }
+          else
+            it { is_expected.to contain_package('mod_security_crs') }
+          end
 
           if (facts[:os]['release']['major'].to_i > 6 && facts[:os]['release']['major'].to_i <= 7) || (facts[:os]['release']['major'].to_i >= 8)
             it {
@@ -73,7 +78,10 @@
             )
           }
 
-          if facts[:os]['release']['major'].to_i <= 7
+          if facts[:os]['release']['major'].to_i >= 10
+            # EL10 is engine-only (no CRS package), so no rules are activated.
+            it { is_expected.not_to contain_apache__security__rule_link('rules/crawlers-user-agents.data') }
+          elsif facts[:os]['release']['major'].to_i <= 7
             it { is_expected.to contain_apache__security__rule_link('base_rules/modsecurity_35_bad_robots.data') }
 
             it {
@@ -384,4 +392,50 @@
       end
     end
   end
+
+  # FacterDB does not yet ship a RedHat-named EL10 factset, so on_supported_os
+  # cannot generate a redhat-10 context. Exercise the engine-only EL10 path
+  # explicitly with hardcoded facts.
+  context 'on RedHat 10 (engine-only via EPEL)' do
+    let :facts do
+      {
+        os: {
+          'architecture' => 'x86_64',
+          'family'       => 'RedHat',
+          'hardware'     => 'x86_64',
+          'name'         => 'RedHat',
+          'release'      => { 'full' => '10.0', 'major' => '10' },
+          'selinux'      => { 'enabled' => false },
+        },
+      }
+    end
+
+    it { is_expected.to compile.with_all_deps }
+
+    it {
+      expect(subject).to contain_apache__mod('security').with(
+        id: 'security2_module',
+        lib: 'mod_security2.so',
+      )
+    }
+
+    it {
+      expect(subject).to contain_apache__mod('unique_id').with(
+        id: 'unique_id_module',
+        lib: 'mod_unique_id.so',
+      )
+    }
+
+    # EL10 ships the engine via EPEL but not the mod_security_crs package, so
+    # the CRS package must not be managed and no rules are activated.
+    it { is_expected.not_to contain_package('mod_security_crs') }
+    it { is_expected.not_to contain_apache__security__rule_link('rules/crawlers-user-agents.data') }
+
+    # The engine config is still written.
+    it {
+      expect(subject).to contain_file('security.conf').with(
+        path: '/etc/httpd/conf.modules.d/security.conf',
+      )
+    }
+  end
 end