SMTP_PASS UnicodeDecodeError after migration to v25.11.29

[lucazade]

Bug Description

After migrating from v25.10.1 to v25.11.29, the SMTP plugin fails with a UnicodeDecodeError when trying to send notifications, even after re-saving settings as instructed.

Environment

• Version: v25.11.29
• Migration from: v25.10.1
• Plugin: SMTP Email Publisher

Error Log

UnicodeDecodeError: 'utf-8' codec can't decode byte 0xa7 in position 0: invalid start byte

Full traceback:

12:50:24 [Send API] Updating notification_* files in  /tmp/api/
12:50:24 [Notification] Udating API files
12:50:24 [Plugin utils] ---------------------------------------------
12:50:24 [Plugin utils]  display_name :  Email publisher (SMTP)
12:50:24 [Plugins] Executing: python3 /app/front/plugins/_publisher_email/email_smtp.py
12:50:24 [plugin_helper] reading config file
12:50:24 [SMTP](publisher) In script
12:50:24 [Database] Opening DB
12:50:24 [SMTP] SMTP_SERVER:  smtp.gmail.com
12:50:24 [SMTP] SMTP_PORT:  587
12:50:24 [SMTP] SMTP_SKIP_LOGIN:  False
12:50:24 [SMTP] SMTP_SKIP_TLS:  False
12:50:24 [SMTP] SMTP_FORCE_SSL:  False
Traceback (most recent call last):
  File "/app/front/plugins/_publisher_email/email_smtp.py", line 243, in <module>
    sys.exit(main())
             ^^^^^^
  File "/app/front/plugins/_publisher_email/email_smtp.py", line 78, in main
    result = send(notification["HTML"], notification["Text"])
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/app/front/plugins/_publisher_email/email_smtp.py", line 158, in send
    send_email(msg, smtp_timeout)
  File "/app/front/plugins/_publisher_email/email_smtp.py", line 213, in send_email
    smtp_connection.login(get_setting_value('SMTP_USER'), get_setting_value('SMTP_PASS'))
                                                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/app/server/helper.py", line 254, in get_setting_value
    value = setting_value_to_python_type(set_type, set_value)
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/app/server/helper.py", line 298, in setting_value_to_python_type
    value = reverseTransformers(str(set_value), transformers)
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/app/server/helper.py", line 405, in reverseTransformers
    return reverse_transformers(val, transformers)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/app/server/helper.py", line 396, in reverse_transformers
    value = base64.b64decode(value).decode("utf-8")
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xa7 in position 0: invalid start byte

12:50:24 [Plugins] ⚠ ERROR - enable LOG_LEVEL=debug and check logs
12:50:24 [Plugins] No output received from the plugin "SMTP"

Steps to Reproduce

1. Migrate from v25.10.1 to v25.11.29 following official migration guide
2. Have SMTP notifications configured in v25.10.1 (working before migration)
3. Re-save settings as instructed in release notes
4. Trigger a notification (e.g., new device detection)
5. Check logs - SMTP plugin fails with UnicodeDecodeError

(The same issue occurs also using dev image and db from scratch)

Expected Behavior

SMTP notifications should work after migration and re-saving settings.

Actual Behavior

SMTP plugin crashes with encoding error when trying to decode SMTP_PASS.

[jokob-sk]

Hi @lucazade ,

Regrettably I can't reproduce your error. Smtp notifications seem to be working fine on my end. The error might be caused by specific character in your password.

Could you please try to narrow down the issue further and let me know which characters are causing the problem? You can also send an email to netalertx@gmail.com with the password causing the error.

Thanks in advance,
J

[RompitaKablo]

Getting the same error since upgrading.

The password is a 16-digit alpha-only passcode from Google and worked prior to the upgrade.

Traceback (most recent call last):
  File "/app/front/plugins/_publisher_email/email_smtp.py", line 243, in <module>
    sys.exit(main())
             ^^^^^^
  File "/app/front/plugins/_publisher_email/email_smtp.py", line 78, in main
    result = send(notification["HTML"], notification["Text"])
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/app/front/plugins/_publisher_email/email_smtp.py", line 158, in send
    send_email(msg, smtp_timeout)
  File "/app/front/plugins/_publisher_email/email_smtp.py", line 213, in send_email
    smtp_connection.login(get_setting_value('SMTP_USER'), get_setting_value('SMTP_PASS'))
                                                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/app/server/helper.py", line 254, in get_setting_value
    value = setting_value_to_python_type(set_type, set_value)
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/app/server/helper.py", line 298, in setting_value_to_python_type
    value = reverseTransformers(str(set_value), transformers)
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/app/server/helper.py", line 405, in reverseTransformers
    return reverse_transformers(val, transformers)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/app/server/helper.py", line 396, in reverse_transformers
    value = base64.b64decode(value).decode("utf-8")
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xb9 in position 7: invalid start byte

00:03:03 [Plugins] ⚠ ERROR - enable LOG_LEVEL=debug and check logs
00:03:03 [Plugins] No output received from the plugin "SMTP"

[jokob-sk]

Hi @RompitaKablo ,

Regrettably I can't reproduce your error. Smtp notifications seem to be working fine on my end. The error might be caused by specific character in your password.

Could you please try to narrow down the issue further and let me know which characters are causing the problem? You can also send an email to netalertx@gmail.com with the password causing the error.

Thanks in advance,
J

[lucazade]

Update: I think I found the issue! 🤔

I noticed that the password is being saved in plaintext with quotes instead of base64-encoded:

/ $ grep "SMTP_PASS" /data/config/app.conf
SMTP_PASS='my-plain-password'

But looking at the metadata, it seems it should be base64-encoded:

"transformers": ["base64"]

When I test the retrieval, I get the same error from the logs:

/ $ python3 << 'EOF'
import sys
sys.path.insert(0, '/app/server')

from helper import get_setting_value

try:
    password = get_setting_value('SMTP_PASS')
    print(f"✅ Password retrieved: {password}")
except Exception as e:
    print(f"❌ ERROR: {e}")
    import traceback
    traceback.print_exc()
EOF

❌ ERROR: 'utf-8' codec can't decode byte 0xa7 in position 0: invalid start byte
Traceback (most recent call last):
  File "<stdin>", line 7, in <module>
  File "/app/server/helper.py", line 254, in get_setting_value
    value = setting_value_to_python_type(set_type, set_value)
  File "/app/server/helper.py", line 298, in setting_value_to_python_type
    value = reverseTransformers(str(set_value), transformers)
  File "/app/server/helper.py", line 405, in reverseTransformers
    return reverse_transformers(val, transformers)
  File "/app/server/helper.py", line 396, in reverse_transformers
    value = base64.b64decode(value).decode("utf-8")
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xa7 in position 0: invalid start byte

So maybe the issue is in the save function? It looks like it's not applying the base64 transformer when writing to the config file. The read function (line 396) seems to correctly try to decode base64, but finds plaintext instead.

Just FYI: My password contains only alphanumeric characters, so I don't think it's a special character issue.

Hope this helps! Let me know if you need any other info. 🙂

[RompitaKablo]

Thank you @lucazade

I replaced the plain-text password in app.conf with a base64 encoded version and my SMTP publisher now works.

[jokob-sk]

This will be fixed in the next release. The password will be pre-pended with base64:val to distinguish between already encoded values. This should happen automatically. you can test thin in the netalertx-dev image in about 5 min.

[lucazade]

I tried the latest dev release but still doesn't work, I get the same issue.

This is in app.conf:

SMTP_PASS='base64:my-plain-password'

This is the related log:

15:55:25 [Plugin utils] ---------------------------------------------
15:55:25 [Plugin utils]  display_name :  Email publisher (SMTP)
15:55:25 [Plugins] Executing: python3 /app/front/plugins/_publisher_email/email_smtp.py
15:55:26 [plugin_helper] reading config file
15:55:25 [SMTP](publisher) In script
15:55:25 [Database] Opening DB
15:55:25 [SMTP] SMTP_SERVER:  smtp.gmail.com
15:55:25 [SMTP] SMTP_PORT:  587
15:55:25 [SMTP] SMTP_SKIP_LOGIN:  False
15:55:25 [SMTP] SMTP_SKIP_TLS:  False
15:55:25 [SMTP] SMTP_FORCE_SSL:  False
Traceback (most recent call last):
  File "/app/front/plugins/_publisher_email/email_smtp.py", line 243, in <module>
    sys.exit(main())
             ^^^^^^
  File "/app/front/plugins/_publisher_email/email_smtp.py", line 78, in main
    result = send(notification["HTML"], notification["Text"])
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/app/front/plugins/_publisher_email/email_smtp.py", line 158, in send
    send_email(msg, smtp_timeout)
  File "/app/front/plugins/_publisher_email/email_smtp.py", line 213, in send_email
    smtp_connection.login(get_setting_value('SMTP_USER'), get_setting_value('SMTP_PASS'))
                                                          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/app/server/helper.py", line 254, in get_setting_value
    value = setting_value_to_python_type(set_type, set_value)
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/app/server/helper.py", line 298, in setting_value_to_python_type
    value = reverseTransformers(str(set_value), transformers)
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/app/server/helper.py", line 431, in reverseTransformers
    return reverse_transformers(val, transformers)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/app/server/helper.py", line 420, in reverse_transformers
    value = base64.b64decode(encoded_part).decode("utf-8")
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xa7 in position 0: invalid start byte

Note: When I manually changed app.conf in stable release to have the password already base64-encoded (without the base64: prefix), it worked

[jokob-sk]

Thanks for testing! Ah, you are right, but can't think of a way to fix it with the current setup (without the base64: prefix. The prefix will prevent the issue in future. What I think is happening:

1. During the time settings are saved the saved value is checked if it matches the base64 format
2. If it matches, (if it is a valid base64 string) it is not re-encoded into base64 (as it is already considered encoded) and stored
3. If it is not a base64 string, it is encoded into base64 to prevent invalid characters breaking the app.conf file
4. Your password(s) probably pass the isBase64 check (they look like base64 encoded already) so the app doesn't re-encode it
5. During settings resolution, the app assumes it's handling base64 encoded values so decodes them before use (before authentication for the SMTP server)

With the above change, base64 encoded values (starting with this setting) will be prefixed with base64: hopefully guaranteeing the issue won't happen again after the password gets saved into base64. A workaround for the latest version should be:

1. Clear the existing SMTP_PASS in the UI
2. Enter your SMTP_PASS
3. Click Save

The above should re-generate the password in the base64:<base64 encoded password>.

[lucazade]

I followed your workaround and it works now!

After clearing the field and re-entering the password, it's now correctly saved as:

SMTP_PASS='base64:<base64_encoded_password>'

And SMTP notifications are working correctly.

Happy to test further if needed. 👍