The TeleMessage archiving backend through 2025-05-05 holds cleartext copies of messages from TM SGNL (aka Archive Signal) app users, which is different functionality than described in the TeleMessage "End-to-End encryption from the mobile phone through to the corporate archive" documentation, as exploited in the wild in May 2025.
CISA has listed this vulnerability in the Known Exploited Vulnerabilities catalog.
The TeleMessage archiving backend through 2025-05-05 holds cleartext copies of messages from TM SGNL (aka Archive Signal) app users, which is different functionality than described in the TeleMessage "End-to-End encryption from the mobile phone through to the corporate archive" documentation, as exploited in the wild in May 2025.
Confirm exposure before applying a vendor-supported change.
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Due date: 2025.06.02Confirm that TeleMessage TM SGNL and an affected version are present.
Combine exploitation signals with asset exposure and business criticality.
Follow the vendor advisory or supported update path and preserve rollback options.
Recheck the version, service health, access paths, and relevant logs.
