diff --git a/packages/platform-crossgram/src/index.ts b/packages/platform-crossgram/src/index.ts
index 065c658b..1b8b5cd7 100644
--- a/packages/platform-crossgram/src/index.ts
+++ b/packages/platform-crossgram/src/index.ts
@@ -2592,7 +2592,7 @@ function formatError(error: unknown): string {
 
 function mapConversation(input: WireConversation): IMConversation<QQMediaLocator> {
   const selfPermissions = input.selfRole ? permissions(input.selfRole) : undefined
-  return {
+  return sanitizeDbStrings({
     id: input.id,
     kind: input.kind,
     title: input.title,
@@ -2607,7 +2607,7 @@ function mapConversation(input: WireConversation): IMConversation<QQMediaLocator
       ...(input.participantCount === undefined ? {} : { participantsCount: input.participantCount }),
       ...(input.selfRole ? { qqSelfRole: input.selfRole } : {}),
     },
-  }
+  })
 }
 
 function mapRequest(input: WireRequest): IMRequest<QQMediaLocator> {
@@ -2700,7 +2700,7 @@ function mapMessage(
   stickerProviderId = 'qqnt:stickers',
   projectMedia?: (media: IMMedia<QQMediaLocator>) => IMMedia<QQMediaLocator>,
 ): IMMessage<QQMediaLocator> {
-  return {
+  return sanitizeDbStrings({
     id: input.id,
     sourceIds: input.sourceIds,
     conversationId: input.conversationId,
@@ -2736,7 +2736,7 @@ function mapMessage(
       parts: mapParts(input, stickerProviderId, reactionCatalog, projectMedia),
       inlineKeyboard: mapInlineKeyboard(input),
     },
-  }
+  })
 }
 
 
@@ -2782,7 +2782,7 @@ function mapParts(
   for (const part of input.parts) {
     if (part.type === 'text') {
       if (markdownText && !part.entities?.length && markdownText.includes(compactText(part.text))) continue
-      const normalized = normalizeTextPart(part, reactionCatalog)
+      const normalized = stripNulTextPart(normalizeTextPart(part, reactionCatalog))
       const previous = parts.at(-1)
       if (previous?.type === 'text') {
         const offset = previous.text.length
@@ -2795,7 +2795,7 @@ function mapParts(
         parts.push(normalized)
       }
     } else if (part.type === 'markdown') {
-      const normalized = parseQQMarkdown(part.content)
+      const normalized = stripNulTextPart(parseQQMarkdown(part.content))
       if (normalized.text) parts.push(normalized)
     } else if (part.type === 'inline-keyboard') {
       continue
@@ -2838,6 +2838,38 @@ function mapParts(
   return parts
 }
 
+function stripNulTextPart(
+  part: Extract<IMMessage<QQMediaLocator>['content']['parts'][number], { type: 'text' }>,
+): typeof part {
+  const text = sanitizeDbString(part.text)
+  if (text === part.text) return part
+  const mappedOffset = (offset: number) => sanitizeDbString(part.text.slice(0, offset)).length
+  const entities = part.entities?.map((entity) => ({
+    ...entity,
+    offset: mappedOffset(entity.offset),
+    length: mappedOffset(entity.offset + entity.length) - mappedOffset(entity.offset),
+  })).filter((entity) => entity.length > 0)
+  return { ...part, text, entities }
+}
+
+function sanitizeDbString(value: string): string {
+  return value.replace(/\0|[\uD800-\uDBFF](?![\uDC00-\uDFFF])|(?<![\uD800-\uDBFF])[\uDC00-\uDFFF]/g, '')
+}
+
+function sanitizeDbStrings<T>(value: T): T {
+  if (typeof value === 'string') return sanitizeDbString(value) as T
+  if (Array.isArray(value)) return value.map(sanitizeDbStrings) as T
+  if (!value || typeof value !== 'object' || Object.getPrototypeOf(value) !== Object.prototype) return value
+  let changed = false
+  const output: Record<string, unknown> = {}
+  for (const [key, item] of Object.entries(value)) {
+    const clean = sanitizeDbStrings(item)
+    output[key] = clean
+    if (clean !== item) changed = true
+  }
+  return changed ? output as T : value
+}
+
 function compactText(value: string): string {
   return value.replace(/\s+/g, '')
 }
diff --git a/packages/platform-crossgram/src/message-order.e2e.test.ts b/packages/platform-crossgram/src/message-order.e2e.test.ts
index 7a8ab1a9..a77ee5a2 100644
--- a/packages/platform-crossgram/src/message-order.e2e.test.ts
+++ b/packages/platform-crossgram/src/message-order.e2e.test.ts
@@ -677,7 +677,7 @@ describe('QQNT zero-peer quarantine E2E', () => {
 })
 
 describe('QQNT durable event checkpoint E2E', () => {
-  it('consumes a replayed message edit and immediately delivers the following reaction update', async () => {
+  it('sanitizes a replayed message edit and delivers the following reaction update', async () => {
     const ctx = new Context()
     const fibers = [
       ctx.plugin(Database),
@@ -726,7 +726,8 @@ describe('QQNT durable event checkpoint E2E', () => {
             id: targetId, conversationId: conversation.id, senderId: checkpointSession.userId,
             timestamp: 1_787_215_084, outgoing: true,
             msgSeq: '463806', telegramMessageId: 463806,
-            parts: [{ type: 'text', text: 'after edit' }],
+            sender: { id: checkpointSession.userId, name: 'Name\uD800', alias: 'bad\0alias' },
+            parts: [{ type: 'text', text: 'after\0 edit' }],
           },
         },
       }))
@@ -773,6 +774,8 @@ describe('QQNT durable event checkpoint E2E', () => {
     const reactionDelivered = Promise.withResolvers<void>()
     const unsubscribe = await platform.subscribe(checkpointSession, async (event) => {
       if (event.type === 'message-edit') {
+        expect(event.message.senderTitle).toBe('badalias')
+        expect(event.message.sender?.firstName).toBe('Name')
         await store.ingest(checkpointSession, event.conversation, event.message)
       } else if (event.type === 'message-reactions') {
         await store.setReactions(checkpointSession, event.conversation, event.target, event.context)
diff --git a/packages/platform-crossgram/src/platform.test.ts b/packages/platform-crossgram/src/platform.test.ts
index cd266b5b..8a0c60d7 100644
--- a/packages/platform-crossgram/src/platform.test.ts
+++ b/packages/platform-crossgram/src/platform.test.ts
@@ -1724,6 +1724,29 @@ describe('QQNTPlatform mapping', () => {
     })
   })
 
+  it('removes QQ text NUL bytes while preserving mention offsets', async () => {
+    const platform = new QQNTPlatform()
+    platform.client.getHistory = vi.fn(async () => ({
+      messages: [{
+        id: 'nul-message', conversationId: '2:group', senderId: 'alice', timestamp: 1, outgoing: false,
+        sender: { id: 'alice', name: 'A\uD800', alias: 'bad\0alias' },
+        parts: [{
+          type: 'text' as const, text: '@abc\0def',
+          entities: [{ type: 'mention' as const, offset: 0, length: 8, userId: 'alice' }],
+        }],
+      }],
+    }))
+
+    const history = await platform.getHistory(session, { id: '2:group' })
+    expect(history.messages[0].content.parts).toMatchObject([{
+      type: 'text', text: '@abcdef',
+      entities: [{ type: 'mention', offset: 0, length: 7, userId: 'alice' }],
+    }])
+    expect(history.messages[0]).toMatchObject({
+      senderTitle: 'badalias', sender: { firstName: 'A', metadata: { qqName: 'A' } },
+    })
+  })
+
   it('publishes the exact size and version of a relayed QQ face sticker', async () => {
     const platform = new QQNTPlatform()
     platform.client.getReactionCatalog = vi.fn(async () => ({ available: [], reactions: [], maxSelected: 20 }))