CVE-2026-54047Network attack vector

Account impersonation via client-controlled OAuth UID

Published Sep 11, 2026 · Updated Sep 11, 2026

Improper authentication in Laci Synchroni Backend before 1.2.3 allows remote authenticated users to impersonate any account through OAuth2 login. SecretKeyAuthenticatorService.AuthorizeOauthAsync trusts a client-controlled UID in config.json instead of binding it to the verified OAuth2 identity. Editing that UID before login returns the target account's session token, granting the authenticated attacker full account access.

CVSS severityUnavailable
Unscored
EPSS probability0.23%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper authentication in Laci Synchroni Backend before 1.2.3 allows remote authenticated users to impersonate any account through OAuth2 login. SecretKeyAuthenticatorService.AuthorizeOauthAsync trusts a client-controlled UID in config.json instead of binding it to the verified OAuth2 identity. Editing that UID before login returns the target account's session token, granting the authenticated attacker full account access.

The record

CVE
CVE-2026-54047
Published
Sep 11, 2026
Updated
Sep 11, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
T1078
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 11, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 11, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

No CVSS assessment is available in this record.

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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1078Valid Accounts

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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