From 54bd554166193714d1318cc00a7fed8a1cb986d7 Mon Sep 17 00:00:00 2001
From: gabriellsh <40830821+gabriellsh@users.noreply.github.com>
Date: Wed, 28 Jan 2026 16:24:31 -0300
Subject: [PATCH] fix(e2ee): Subscription's `lastMessage` not properly
 decrypting (#38283)

---
 .changeset/cold-coats-cross.md                |  5 +++++
 .../client/lib/e2ee/rocketchat.e2e.room.ts    | 22 +++++++++++++------
 apps/meteor/client/lib/e2ee/rocketchat.e2e.ts | 17 +++++++++++++-
 3 files changed, 36 insertions(+), 8 deletions(-)
 create mode 100644 .changeset/cold-coats-cross.md

diff --git a/.changeset/cold-coats-cross.md b/.changeset/cold-coats-cross.md
new file mode 100644
index 00000000000..12dbfd710ce
--- /dev/null
+++ b/.changeset/cold-coats-cross.md
@@ -0,0 +1,5 @@
+---
+"@rocket.chat/meteor": patch
+---
+
+Fixes an issue with encrypted room's message previews on the sidebar not always being properly decrypted
diff --git a/apps/meteor/client/lib/e2ee/rocketchat.e2e.room.ts b/apps/meteor/client/lib/e2ee/rocketchat.e2e.room.ts
index f5350573839..9d611183e0a 100644
--- a/apps/meteor/client/lib/e2ee/rocketchat.e2e.room.ts
+++ b/apps/meteor/client/lib/e2ee/rocketchat.e2e.room.ts
@@ -666,18 +666,26 @@ export class E2ERoom extends Emitter {
 			return message;
 		}
 
-		// TODO(@cardoso): review backward compatibility
-		if (message.msg && !isEncryptedMessageContent(message)) {
-			const data = await this.decrypt(message.msg);
-			if (data.msg) {
-				message.msg = data.msg;
-			}
+		if (isEncryptedMessageContent(message)) {
+			return {
+				...(await this.decryptContent({ ...message })),
+				e2e: 'done' as const,
+			};
 		}
 
-		message = isEncryptedMessageContent(message) ? await this.decryptContent(message) : message;
+		if (!message.msg) {
+			return {
+				...message,
+				e2e: 'done' as const,
+			};
+		}
+
+		// TODO(@cardoso): review backward compatibility
+		const data = await this.decrypt(message.msg);
 
 		return {
 			...message,
+			msg: typeof data.msg === 'string' ? data.msg : message.msg,
 			e2e: 'done' as const,
 		};
 	}
diff --git a/apps/meteor/client/lib/e2ee/rocketchat.e2e.ts b/apps/meteor/client/lib/e2ee/rocketchat.e2e.ts
index 2eaae8474cf..fa882495507 100644
--- a/apps/meteor/client/lib/e2ee/rocketchat.e2e.ts
+++ b/apps/meteor/client/lib/e2ee/rocketchat.e2e.ts
@@ -671,7 +671,22 @@ class E2E extends Emitter {
 		const span = log.span('decryptSubscription');
 		const e2eRoom = await this.getInstanceByRoomId(subscription.rid);
 		span.info(subscription._id);
-		await e2eRoom?.decryptSubscription();
+
+		if (!e2eRoom) {
+			span.warn('no e2eRoom found');
+			return;
+		}
+
+		if (e2eRoom.isReady()) {
+			span.info('e2e room ready');
+			await e2eRoom.decryptSubscription();
+			return;
+		}
+
+		e2eRoom.once('READY', async () => {
+			span.info('e2e room ready');
+			await e2eRoom.decryptSubscription();
+		});
 	}
 
 	async decryptSubscriptions(): Promise<void> {