diff --git a/scripts/deploy-selfhost-image.sh b/scripts/deploy-selfhost-image.sh
index acac51ca3c..c3b9b87fe0 100755
--- a/scripts/deploy-selfhost-image.sh
+++ b/scripts/deploy-selfhost-image.sh
@@ -108,7 +108,13 @@ services:
     build: !reset null
 YAML
 
-mapfile -t compose_args < <(compose_file_args)
+# #7765: capture via a checked assignment so compose_file_args's `exit 1` on a missing compose file
+# actually aborts this script -- `mapfile < <(compose_file_args)` ran it in a subshell whose non-zero
+# exit was swallowed (mapfile itself returns 0), leaving compose_args empty/truncated.
+if ! compose_args_raw="$(compose_file_args)"; then
+  exit 1
+fi
+mapfile -t compose_args <<< "$compose_args_raw"
 compose_args+=(-f "$override_file")
 
 echo "selfhost image deploy: ensuring secret placeholder files exist"
diff --git a/scripts/deploy-selfhost-prebuilt.sh b/scripts/deploy-selfhost-prebuilt.sh
index 225ef34539..0080c1c20f 100755
--- a/scripts/deploy-selfhost-prebuilt.sh
+++ b/scripts/deploy-selfhost-prebuilt.sh
@@ -104,7 +104,13 @@ services:
       LOOPOVER_VERSION: "\${SENTRY_RELEASE}"
 YAML
 
-  mapfile -t compose_args < <(compose_file_args)
+  # #7765: capture via a checked assignment so compose_file_args's `exit 1` on a missing compose file
+  # actually aborts this script -- `mapfile < <(compose_file_args)` ran it in a subshell whose non-zero
+  # exit was swallowed (mapfile itself returns 0), leaving compose_args empty/truncated.
+  if ! compose_args_raw="$(compose_file_args)"; then
+    exit 1
+  fi
+  mapfile -t compose_args <<< "$compose_args_raw"
   compose_args+=(-f "$override_file")
 
   echo "selfhost deploy: building $SERVICE runtime-prebuilt image"
diff --git a/scripts/selfhost-post-update-check.sh b/scripts/selfhost-post-update-check.sh
index f697d909bd..4ec4895b53 100755
--- a/scripts/selfhost-post-update-check.sh
+++ b/scripts/selfhost-post-update-check.sh
@@ -22,7 +22,13 @@ require_cmd docker
 require_cmd curl
 docker compose version >/dev/null
 
-mapfile -t compose_args < <(compose_file_args)
+# #7765: capture via a checked assignment so compose_file_args's `exit 1` on a missing compose file
+# actually aborts this script -- `mapfile < <(compose_file_args)` ran it in a subshell whose non-zero
+# exit was swallowed (mapfile itself returns 0), leaving compose_args empty/truncated.
+if ! compose_args_raw="$(compose_file_args)"; then
+  exit 1
+fi
+mapfile -t compose_args <<< "$compose_args_raw"
 
 container_id="$(docker compose "${compose_args[@]}" ps -q "$SERVICE" 2>/dev/null || true)"
 if [ -z "$container_id" ]; then
diff --git a/scripts/selfhost-post-update-regression-gate.sh b/scripts/selfhost-post-update-regression-gate.sh
index 10d1024528..788dee6be9 100755
--- a/scripts/selfhost-post-update-regression-gate.sh
+++ b/scripts/selfhost-post-update-regression-gate.sh
@@ -41,7 +41,13 @@ if [[ ! "$THRESHOLD" =~ ^[0-9]+$ ]]; then
   THRESHOLD=5
 fi
 
-mapfile -t compose_args < <(compose_file_args)
+# #7765: capture via a checked assignment so compose_file_args's `exit 1` on a missing compose file
+# actually aborts this script -- `mapfile < <(compose_file_args)` ran it in a subshell whose non-zero
+# exit was swallowed (mapfile itself returns 0), leaving compose_args empty/truncated.
+if ! compose_args_raw="$(compose_file_args)"; then
+  exit 1
+fi
+mapfile -t compose_args <<< "$compose_args_raw"
 
 container_id="$(docker compose "${compose_args[@]}" ps -q "$SERVICE" 2>/dev/null || true)"
 if [ -z "$container_id" ]; then
diff --git a/test/unit/selfhost-deploy-common.test.ts b/test/unit/selfhost-deploy-common.test.ts
index c359483feb..61a6719483 100644
--- a/test/unit/selfhost-deploy-common.test.ts
+++ b/test/unit/selfhost-deploy-common.test.ts
@@ -175,3 +175,55 @@ describe("env_put (#7766 -- atomic write + mode preservation)", () => {
     }
   });
 });
+
+describe("compose_file_args exit propagation (#7765)", () => {
+  // The exact idiom the callers (deploy-selfhost-image.sh etc.) now use to consume compose_file_args.
+  // Under the old `mapfile -t compose_args < <(compose_file_args)` the function ran in a subshell whose
+  // `exit 1` on a missing file was swallowed (mapfile returns 0), so the caller continued with an
+  // empty/truncated -f arg list. The checked assignment must instead abort before REACHED_END.
+  const CONSUMER = `
+set -euo pipefail
+. "${libPath.replace(/\\/g, "/")}"
+if ! compose_args_raw="$(compose_file_args)"; then
+  exit 1
+fi
+mapfile -t compose_args <<< "$compose_args_raw"
+printf 'REACHED_END args=[%s]\\n' "\${compose_args[*]}"
+`;
+
+  function runConsumer(env: Record<string, string> = {}) {
+    const dir = mkdtempSync(join(tmpdir(), "loopover-compose-args-"));
+    try {
+      // Give the default-branch a real docker-compose.yml so the happy path has a file to find.
+      writeFileSync(join(dir, "docker-compose.yml"), "services: {}\n");
+      writeFileSync(join(dir, "base.yml"), "services: {}\n");
+      return spawnSync("bash", ["-c", CONSUMER], {
+        cwd: dir,
+        encoding: "utf8",
+        env: { ...process.env, ...env },
+      });
+    } finally {
+      rmSync(dir, { recursive: true, force: true });
+    }
+  }
+
+  it("continues with the -f args when every compose file exists", () => {
+    const result = runConsumer();
+    expect(result.status, result.stderr).toBe(0);
+    expect(result.stdout).toContain("REACHED_END args=[-f docker-compose.yml]");
+  });
+
+  it("aborts (never reaching the consumer) when the sole compose file is missing", () => {
+    const result = runConsumer({ SELFHOST_COMPOSE_FILES: "does-not-exist.yml" });
+    expect(result.status).not.toBe(0);
+    expect(result.stdout).not.toContain("REACHED_END");
+    expect(result.stderr).toContain("compose file not found: does-not-exist.yml");
+  });
+
+  it("aborts instead of continuing with a TRUNCATED arg list when a later compose file is missing", () => {
+    const result = runConsumer({ SELFHOST_COMPOSE_FILES: "base.yml missing.yml" });
+    expect(result.status).not.toBe(0);
+    expect(result.stdout).not.toContain("REACHED_END");
+    expect(result.stderr).toContain("compose file not found: missing.yml");
+  });
+});