diff --git a/CHANGELOG.md b/CHANGELOG.md
index 074bb8b6..a5ba355a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,20 @@
 # Changelog
 
+## 2.6.13
+
+### Fixed: mid-severity findings were dropped from the Slack summary
+
+- The Slack reachability formatter keyed every severity lookup on `medium`,
+  but the API sends `middle`. A mid-severity finding therefore missed all of
+  them at once: it was not counted, so the summary always read `Medium: 0`; it
+  was excluded from `total_findings`, which can drive the "and N more" count
+  negative; and it sorted at the default order of 4, below `low`, so it was the
+  first thing truncated when the Slack block limit was reached.
+- Severity is now normalized to one spelling when an alert is read, matching
+  how the GitLab and PR-comment paths already handle both forms. The findings
+  themselves were always listed; only the counts, ordering and truncation were
+  wrong.
+
 ## 2.6.12
 
 ### Fixed: unreadable reachability facts no longer report a blocking package
diff --git a/pyproject.toml b/pyproject.toml
index b85e8b80..8f513c72 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -6,7 +6,7 @@ build-backend = "hatchling.build"
 
 [project]
 name = "socketsecurity"
-version = "2.6.12"
+version = "2.6.13"
 requires-python = ">= 3.11"
 license = {"file" = "LICENSE"}
 dependencies = [
diff --git a/socketsecurity/__init__.py b/socketsecurity/__init__.py
index c1ba543c..ce2d5859 100644
--- a/socketsecurity/__init__.py
+++ b/socketsecurity/__init__.py
@@ -1,3 +1,3 @@
 __author__ = 'socket.dev'
-__version__ = '2.6.12'
+__version__ = '2.6.13'
 USER_AGENT = f'SocketPythonCLI/{__version__}'
diff --git a/socketsecurity/plugins/formatters/slack.py b/socketsecurity/plugins/formatters/slack.py
index adce7eec..904f5f3d 100644
--- a/socketsecurity/plugins/formatters/slack.py
+++ b/socketsecurity/plugins/formatters/slack.py
@@ -108,6 +108,12 @@ def _extract_alert_info(component: Dict[str, Any], alert: Dict[str, Any]) -> Dic
     """
     props = alert.get('props', {}) or {}
     severity = str(alert.get('severity') or props.get('severity') or '').lower()
+    # The API's mid-level severity is "middle"; every lookup in this module is
+    # keyed on "medium". Normalizing here rather than adding a parallel key to
+    # each dict keeps one canonical spelling downstream, matching what
+    # Messages.map_socket_severity_to_gitlab already does.
+    if severity == 'middle':
+        severity = 'medium'
     
     return {
         'cve_id': str(props.get('ghsaId') or props.get('cveId') or alert.get('title') or 'Unknown'),
diff --git a/tests/unit/test_slack_severity_normalization.py b/tests/unit/test_slack_severity_normalization.py
new file mode 100644
index 00000000..861fe34c
--- /dev/null
+++ b/tests/unit/test_slack_severity_normalization.py
@@ -0,0 +1,76 @@
+"""The Slack formatter keys on "medium"; the API sends "middle".
+
+Every severity lookup in ``socketsecurity/plugins/formatters/slack.py`` is keyed
+on ``medium``, but ``middle`` is what the API actually emits -- it is the value
+in the OpenAPI spec's ``SocketIssueSeverity`` and in the SDK enum. Unnormalized,
+a mid-severity finding fell through every one of them at once:
+
+* it was not counted, so the summary always read ``Medium: 0``
+* it was excluded from ``total_findings``, which can drive ``omitted_count``
+  negative when mid-severity findings are the ones being displayed
+* it sorted at the default order of 4, below ``low``, so it was truncated out of
+  the message first when the block limit was reached
+
+Two other call sites already handle both spellings (``Messages.map_socket_
+severity_to_gitlab`` and the GitLab severity map); this formatter did not.
+"""
+
+import unittest
+
+from socketsecurity.plugins.formatters.slack import (
+    SEVERITY_EMOJI,
+    SEVERITY_ORDER,
+    _extract_alert_info,
+    format_socket_facts_for_slack,
+)
+
+
+def _component(severity: str) -> dict:
+    return {
+        "name": "example-package",
+        "version": "1.0.0",
+        "alerts": [{"title": "Example alert", "severity": severity, "props": {}}],
+    }
+
+
+class TestSeverityNormalization(unittest.TestCase):
+    def test_middle_normalizes_to_medium(self):
+        info = _extract_alert_info(_component("middle"), {"severity": "middle"})
+        self.assertEqual(info["severity"], "medium")
+
+    def test_middle_gets_the_medium_order_not_the_default(self):
+        info = _extract_alert_info(_component("middle"), {"severity": "middle"})
+        self.assertEqual(info["severity_order"], SEVERITY_ORDER["medium"])
+        # Regression: the default of 4 sorted mid-severity below "low".
+        self.assertLess(info["severity_order"], SEVERITY_ORDER["low"])
+
+    def test_middle_gets_the_medium_emoji_not_the_fallback(self):
+        info = _extract_alert_info(_component("middle"), {"severity": "middle"})
+        self.assertEqual(info["severity_emoji"], SEVERITY_EMOJI["medium"])
+        self.assertNotEqual(info["severity_emoji"], SEVERITY_EMOJI["low"])
+
+    def test_medium_still_works(self):
+        info = _extract_alert_info(_component("medium"), {"severity": "medium"})
+        self.assertEqual(info["severity"], "medium")
+        self.assertEqual(info["severity_order"], SEVERITY_ORDER["medium"])
+
+    def test_middle_findings_are_counted_in_the_summary(self):
+        result = format_socket_facts_for_slack([_component("middle")])
+        self.assertEqual(len(result), 1)
+        self.assertIn("🟡 Medium: 1", result[0]["summary"])
+
+    def test_middle_findings_reach_total_findings(self):
+        # Regression: excluded from the total, omitted_count could go negative.
+        result = format_socket_facts_for_slack([_component("middle")])
+        self.assertEqual(result[0]["total_findings"], 1)
+
+    def test_unrecognized_severity_still_falls_back(self):
+        info = _extract_alert_info(
+            _component("brand-new-level"), {"severity": "brand-new-level"}
+        )
+        self.assertEqual(info["severity_order"], 4)
+        self.assertEqual(info["severity_emoji"], "⚪")
+
+
+if __name__ == "__main__":
+    unittest.main()
diff --git a/uv.lock b/uv.lock
index 8e880d32..fd652795 100644
--- a/uv.lock
+++ b/uv.lock
@@ -1282,7 +1282,7 @@ wheels = [
 
 [[package]]
 name = "socketsecurity"
-version = "2.6.12"
+version = "2.6.13"
 source = { editable = "." }
 dependencies = [
     { name = "beautifulsoup4" },