From 85f0e60cd9d0f9078b3fae56dbf6c6be406b22c4 Mon Sep 17 00:00:00 2001
From: ryder777777 <sahilridder@gmail.com>
Date: Thu, 22 Oct 2026 13:30:44 +0000
Subject: [PATCH] fix(dedupe): Mark active session as crashed when
 deduplicating unhandled exceptions

---
 sentry_sdk/integrations/dedupe.py      | 17 ++++++++++++++
 tests/integrations/flask/test_flask.py | 31 ++++++++++++++++++++++++++
 2 files changed, 48 insertions(+)

diff --git a/sentry_sdk/integrations/dedupe.py b/sentry_sdk/integrations/dedupe.py
index a0e9014666..fe7f66f3a2 100644
--- a/sentry_sdk/integrations/dedupe.py
+++ b/sentry_sdk/integrations/dedupe.py
@@ -42,6 +42,23 @@ def processor(event: "Event", hint: "Optional[Hint]") -> "Optional[Event]":
 
             exc = exc_info[1]
             if last_seen is exc:
+                exceptions = (event.get("exception") or {}).get("values") or ()
+                for error in exceptions:
+                    mechanism = (
+                        error.get("mechanism") if isinstance(error, dict) else None
+                    )
+                    if (
+                        isinstance(mechanism, dict)
+                        and mechanism.get("handled") is False
+                    ):
+                        session = (
+                            sentry_sdk.get_isolation_scope()._session
+                            or sentry_sdk.get_current_scope()._session
+                        )
+                        if session is not None:
+                            session.update(status="crashed")
+                        break
+
                 logger.info("DedupeIntegration dropped duplicated error event %s", exc)
                 return None
 
diff --git a/tests/integrations/flask/test_flask.py b/tests/integrations/flask/test_flask.py
index 498f74d82e..4de3649da5 100644
--- a/tests/integrations/flask/test_flask.py
+++ b/tests/integrations/flask/test_flask.py
@@ -397,6 +397,37 @@ def index():
     assert session["attrs"]["release"] == "demo-release"
 
 
+def test_flask_session_tracking_log_then_reraise(sentry_init, capture_envelopes, app):
+    sentry_init(
+        integrations=[flask_sentry.FlaskIntegration()],
+        release="demo-release",
+    )
+
+    @app.route("/")
+    def index():
+        try:
+            raise ValueError("db down")
+        except ValueError:
+            logging.exception("failed to load")
+            raise
+
+    envelopes = capture_envelopes()
+
+    with app.test_client() as client:
+        with pytest.raises(ValueError):
+            client.get("/")
+
+    sentry_sdk.flush()
+
+    session_envelopes = [
+        e for e in envelopes if any(item.type == "sessions" for item in e.items)
+    ]
+    assert len(session_envelopes) == 1
+    aggregates = session_envelopes[0].items[0].payload.json["aggregates"]
+    assert sum(agg.get("crashed", 0) for agg in aggregates) == 1
+    assert sum(agg.get("errored", 0) for agg in aggregates) == 0
+
+
 @pytest.mark.parametrize("data", [{}, []], ids=["empty-dict", "empty-list"])
 def test_flask_empty_json_request(sentry_init, capture_events, app, data):
     sentry_init(integrations=[flask_sentry.FlaskIntegration()])