From 7b2a79be2a167403aea45c1968a72432dec6a704 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn=20P=C3=B6ttker?= <bjoern@poettker-holtrup.de>
Date: Wed, 22 Jul 2026 11:10:36 +0200
Subject: [PATCH] fix: Dateinamen mit Pfadtrennzeichen beim Mail-Import
 absichern
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Anhänge mit '/' im Dateinamen (z.B. "Rechnung - 2026/002650322.PDF")
führten zu einem Fehler, weil '/' als Verzeichnistrenner interpretiert
wurde und der temp. Pfad nicht existierte.

- sanitizeFilename() ersetzt '/' und '\' durch '-', entfernt '..' und Null-Bytes
- Wird beim Speichern in die DB (email-download) und beim Aufbau des
  temp. Pfads (email-import) angewendet (defense-in-depth)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
---
 .../src/email-download/email-download.service.ts       | 10 +++++++++-
 paperless-backend/src/email/email-import.service.ts    | 10 +++++++++-
 2 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/paperless-backend/src/email-download/email-download.service.ts b/paperless-backend/src/email-download/email-download.service.ts
index 5ff38cc..561a311 100644
--- a/paperless-backend/src/email-download/email-download.service.ts
+++ b/paperless-backend/src/email-download/email-download.service.ts
@@ -20,6 +20,14 @@ import { Attachment } from '../database/entities/attachment.entity';
 import { Content } from '../database/entities/content.entity';
 import { isERechnung } from './zugferd.util';
 
+function sanitizeFilename(name: string): string {
+  return name
+    .replace(/[/\\]/g, '-')
+    .replace(/\.\./g, '.')
+    .replace(/\x00/g, '')
+    .trim();
+}
+
 @Injectable()
 export class EmailDownloadService {
   private readonly logger = new Logger(EmailDownloadService.name);
@@ -291,7 +299,7 @@ export class EmailDownloadService {
     }
 
     const attachment = new Attachment();
-    attachment.FileName = filename.slice(0, 255);
+    attachment.FileName = sanitizeFilename(filename).slice(0, 255);
     attachment.ContentType = contentType.slice(0, 100);
     attachment.IsEmbedded = isEmbedded;
     attachment.ContentId = att.cid ? att.cid.slice(0, 255) : null;
diff --git a/paperless-backend/src/email/email-import.service.ts b/paperless-backend/src/email/email-import.service.ts
index 884282b..76ab484 100644
--- a/paperless-backend/src/email/email-import.service.ts
+++ b/paperless-backend/src/email/email-import.service.ts
@@ -20,6 +20,14 @@ import * as os from 'os';
 import * as fs from 'fs/promises';
 import * as crypto from 'crypto';
 
+function sanitizeFilename(name: string): string {
+  return name
+    .replace(/[/\\]/g, '-')
+    .replace(/\.\./g, '.')
+    .replace(/\x00/g, '')
+    .trim();
+}
+
 @Injectable()
 export class EmailImportService {
   private readonly logger = new Logger(EmailImportService.name);
@@ -492,7 +500,7 @@ export class EmailImportService {
         if (!content) continue;
 
         const originalPdfBytes = content.Content1;
-        const baseFilename = attachmentEntity.FileName.replace(/\.pdf$/i, '');
+        const baseFilename = sanitizeFilename(attachmentEntity.FileName.replace(/\.pdf$/i, ''));
         const paperlessIds: any = {};
 
         const uploadPromises = [];