diff --git a/apps/backend/requirements.txt b/apps/backend/requirements.txt
index d30157e3..dbafa4ac 100644
--- a/apps/backend/requirements.txt
+++ b/apps/backend/requirements.txt
@@ -69,7 +69,7 @@ email-validator==2.2.0
 # canonical asyncio-native SMTP client; pairs cleanly with httpx for the
 # Slack / Teams webhook channels and avoids spawning threads from the FastAPI
 # event loop just to send mail.
-aiosmtplib==3.0.2
+aiosmtplib==5.1.1
 # Scan-gap G2 — HTML → PDF for the vulnerability report download. weasyprint
 # needs native libs (libpango / cairo / gdk-pixbuf) installed in the image
 # (see apps/backend/Dockerfile* for the apt list). It is imported LAZILY in