Comparison Overview
A1 Srbija d.o.o.

A1 Srbija d.o.o.
Milutina Milankovića 1ž, Belgrade, 11000, RS
Last Update: 20/04/2026
A1 Serbia is a part of A1 Telekom Austria Group, leading provider of digital services and communications solutions in Central and Eastern Europe. Together we are offering a state-of-the art network infrastructure and strive to empower digital life of more than 25 millio...

MTS Group
Moscow, RU
Last Update: 05/09/2026
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 Srbija d.o.o.







MTS Group






Benchmark & Cyber Underwriting Signals
Incidents vs Telecommunications Industry Avg (This Year)
No incidents recorded for A1 Srbija d.o.o. in 2026.
Incidents vs Telecommunications Industry Avg (This Year)
No incidents recorded for MTS Group in 2026.
Incident History - A1 Srbija d.o.o. (X = Date, Y = Severity)
A1 Srbija d.o.o. 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 Srbija d.o.o.

MTS Group
FAQ
Latest Global CVEs
ClassroomIO through 1.0.0 contains an incorrect authorization vulnerability in the PUT and DELETE /:lessonId lesson routes that allows any course member, including students, to modify lessons. Authenticated students can supply arbitrary lesson ids to change titles and stored HTML content or delete lessons in their course and in other courses and organizations.
- https://github.com/classroomio/classroomio
- https://github.com/classroomio/classroomio/blob/v1.0.0/apps/api/src/middlewares/course-member.ts
- https://github.com/classroomio/classroomio/blob/v1.0.0/apps/api/src/routes/course/lesson.ts#L107-L152
- https://hackmd.io/@hieuPenguinnn/classroomio-course-resource-id-scoping-idor
- https://www.vulncheck.com/advisories/classroomio-through-1.0.0-incorrect-authorization-via-lesson-update-and-delete-routes
ClassroomIO through 1.0.0 contains an insecure direct object reference vulnerability in the Hono API course submission routes that allows course tutors or admins to modify submissions in other courses. Attackers can supply their own course id with another course's submission UUID to PUT or DELETE handlers to overwrite answers, grades, feedback, and grading status or delete submissions.
- https://github.com/classroomio/classroomio
- https://github.com/classroomio/classroomio/blob/v1.0.0/apps/api/src/routes/course/submission.ts
- https://github.com/classroomio/classroomio/blob/v1.0.0/packages/db/src/queries/submission/submission.ts#L217-L245
- https://github.com/classroomio/classroomio/commit/1844ad9671a0d9c2566d3431d82f34d39016242c
- https://hackmd.io/@hieuPenguinnn/classroomio-course-resource-id-scoping-idor
- https://www.vulncheck.com/advisories/classroomio-through-1.0.0-idor-via-course-submission-update-grade-and-delete-routes
BillionMail through 4.9 contains a hard-coded cryptographic key vulnerability that allows unauthenticated attackers to forge unsubscribe and subscribe-confirm JWTs by computing the key from shipped configuration constants. Attackers can submit forged tokens to /api/unsubscribe, /api/unsubscribe_new, or /api/subscribe/confirm to deactivate any contact or force confirmed subscriptions.
- https://github.com/aaPanel/BillionMail
- https://github.com/aaPanel/BillionMail/blob/v4.9/core/internal/service/batch_mail/jwt.go#L98-L123
- https://github.com/aaPanel/BillionMail/blob/v4.9/core/manifest/config/config.yaml
- https://hackmd.io/@hieuPenguinnn/billionmail-unsubscribe-subscribe-jwt-deterministic-secret-forgery
- https://www.vulncheck.com/advisories/billionmail-through-4.9-forgeable-jwts-via-default-signing-key
cool-admin-midway through 8.0.0 contains an authorization bypass vulnerability that allows department-limited admins to manage users outside their departments by supplying arbitrary user ids. Attackers holding sys:user:* permissions can call /admin/sys/user/info, update, or delete to read records, reset passwords and roles, or delete accounts.
- https://github.com/cool-team-official/cool-admin-midway
- https://github.com/cool-team-official/cool-admin-midway/blob/e545ef6f3b0c08581e34bd3207ca57d851ccc3ae/src/modules/base/service/sys/user.ts#L205-L229
- https://github.com/cool-team-official/cool-admin-midway/blob/e545ef6f3b0c08581e34bd3207ca57d851ccc3ae/src/modules/base/service/sys/user.ts#L41-L70
- https://hackmd.io/@hieuPenguinnn/cool-admin-midway-base-crud-role-ownership-idor
- https://www.vulncheck.com/advisories/cool-admin-midway-through-8.0.0-authorization-bypass-via-admin-sys-user-endpoints
cool-admin-midway through 8.0.0 contains an authorization bypass vulnerability that allows non-superadmin admins to read, modify, or delete other admins' roles by supplying arbitrary role ids. Attackers holding ordinary sys:role permissions can call /admin/sys/role/info, update, or delete with another admin's role id to rewrite menu and department grants, changing other users' effective access.
- https://github.com/cool-team-official/cool-admin-midway
- https://github.com/cool-team-official/cool-admin-midway/blob/e545ef6f3b0c08581e34bd3207ca57d851ccc3ae/src/modules/base/controller/admin/sys/role.ts#L11-L36
- https://github.com/cool-team-official/cool-admin-midway/blob/e545ef6f3b0c08581e34bd3207ca57d851ccc3ae/src/modules/base/service/sys/role.ts#L54-L118
- https://hackmd.io/@hieuPenguinnn/cool-admin-midway-base-crud-role-ownership-idor
- https://www.vulncheck.com/advisories/cool-admin-midway-through-8.0.0-missing-authorization-via-system-role-endpoints