Comparison Overview
A1 Bulgaria

A1 Bulgaria
1, Kukush Str., Sofia, 1309, BG
Last Update: 26/12/2025
А1 е водещ доставчик на дигитални услуги и телекомуникационни решения в България. Компанията предоставя мобилни и фиксирани услуги, високоскоростен интернет, интерактивна, цифрова и сателитна телевизия, 4 собствени спортни канала с марката MAX Sport, платежни услуги, IC...

MTS Group
Moscow, RU
Last Update: 30/03/2026
Mobile TeleSystems OJSC ("MTS") is the leading telecommunications group in Russia, Eastern Europe and Central Asia, offering mobile and fixed voice, broadband, pay TV as well as content and entertainment services in one of the world's fastest growing regions. Including ...
Compliance Ranges Comparison

A1 Bulgaria







MTS Group






Benchmark & Cyber Underwriting Signals
Incidents vs Telecommunications Industry Avg (This Year)
No incidents recorded for A1 Bulgaria in 2026.
Incidents vs Telecommunications Industry Avg (This Year)
No incidents recorded for MTS Group in 2026.
Incident History - A1 Bulgaria (X = Date, Y = Severity)
A1 Bulgaria cyber incidents detection timeline including parent company and subsidiaries.
Incident History - MTS Group (X = Date, Y = Severity)
MTS Group cyber incidents detection timeline including parent company and subsidiaries.
Notable Incidents

A1 Bulgaria

MTS Group
FAQ
Latest Global CVEs
Buffer Overflow vulnerability in Systerel S2OPC 1.7.3 allows a remote attacker to cause a denial of service via the Alarm/Conditions wrapper when processing PublishResponse EventNotificationList data
- https://github.com/gff-cw/information/issues/18
- https://github.com/systerel/S2OPC/blob/S2OPC_Toolkit_1.7.3/src/ClientServer/address_space/sopc_event_manager.c
- https://github.com/systerel/S2OPC/blob/S2OPC_Toolkit_1.7.3/src/ClientServer/frontend/client_wrapper/alarm_conditions/libs2opc_client_alarm_conditions.c
- https://github.com/systerel/S2OPC/blob/S2OPC_Toolkit_1.7.3/src/ClientServer/frontend/client_wrapper/internal/state_machine.c
- https://gitlab.com/systerel/S2OPC/-/work_items/1781
Buffer Overflow vulnerability in Systerel S2OPC 1.7.3 allows a remote attacker to cause a denial of service via the LockedStaMac_ProcessMsg_DeleteMonitoredItemsResponse and SOPC_StaMac_NewDeleteMonitoredItems in the client wrapper DeleteMonitoredItems path
- https://github.com/gff-cw/information/issues/16
- https://github.com/systerel/S2OPC/blob/master/samples/ClientServer/client_wrapper/examples/subscribe.c
- https://github.com/systerel/S2OPC/blob/master/src/ClientServer/frontend/client_wrapper/internal/state_machine.c
- https://gitlab.com/systerel/S2OPC/-/work_items/1780
In open62541 1.5.5, a server-side use-after-free exists in the local MonitoredItem callback path. The issue occurs when UA_Subscription_localPublish continues to use the current UA_Notification after a callback invokes UA_Server_deleteMonitoredItem for the current local MonitoredItem. This allows a remote attacker to cause a denial of service.
H5Z__filter_nbit in H5Znbit.c in HDF5 through 2.3.0 dereferences cd_values[0] through cd_values[4] without validating that cd_values is non-NULL or that cd_nelmts is at least 5, the fixed size of the filter's header. This allows attackers to cause a denial of service via a crafted HDF5 file that stores the N-Bit filter pipeline message with zero client-data values, opened and read via H5Dread, e.g. by the h5ls or h5repack tools.
H5O__layout_decode in H5Olayout.c in HDF5 through 2.3.0 does not validate that a chunked dataset's stored chunk-layout dimensionality matches its dataspace rank when an existing dataset is opened, whereas this check is performed only at dataset-creation time. This allows attackers to cause a denial of service (divide-by-zero and application crash in H5S__hyper_iter_get_seq_list in src/H5Shyper.c) via a crafted HDF5 file with mismatched chunk/dataspace ranks that is opened and read via H5Dopen2 and H5Dread, e.g. by the h5repack tool.