CVE-2026-3873Network attack vector

Unauthenticated ACL bypass via hard-coded rtm account

Published Mar 13, 2026 · Updated Mar 13, 2026

Hard-coded credentials in Syslink Software AG Avantra before 25.3.0 allow remote attackers to access ACL-restricted functionality. The legacy built-in rtm account validates credentials embedded in the product instead of credentials provisioned uniquely for each deployment. The account requires no prior authenticated session and permits limited data access and modification outside the intended ACL, with no reported service interruption.

CVSS severity7.2
High
EPSS probability0.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Hard-coded credentials in Syslink Software AG Avantra before 25.3.0 allow remote attackers to access ACL-restricted functionality. The legacy built-in rtm account validates credentials embedded in the product instead of credentials provisioned uniquely for each deployment. The account requires no prior authenticated session and permits limited data access and modification outside the intended ACL, with no reported service interruption.

The record

CVE
CVE-2026-3873
Published
Mar 13, 2026
Updated
Mar 13, 2026
Vendor
Syslink Software AG
Product
Avantra
Classifications
CWE-798, T1078
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 13, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 13, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <25.3.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Syslink Software AG · Avantraversion=0 <25.3.0

Published CVSS scores

7.2Switzerland Government Common Vulnerability ProgramCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-798Use of Hard-coded Credentials
T1078Valid Accounts

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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