CVE-2026-49446Public exploitHinoki check available

User impersonation via unstripped forward-auth headers

Published Sep 15, 2026 · Updated Sep 15, 2026

Authentication bypass in Beyond Cloud ltd. Cosmos Server before 0.22.19 allows remote authenticated users to impersonate users via Constellation. In tokenMiddleware, the tunnel bypass returns before stripping attacker-supplied identity and role headers and before enforcing the AdminOnly gate. Exploitation requires an enrolled-device API key, tunnel access, an authentication-enabled proxy route, and an upstream that trusts the header; exposed admin-tier reads and writes then execute under a chosen identity.

CVSS severity6.1
Medium
EPSS probability0.29%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Authentication bypass in Beyond Cloud ltd. Cosmos Server before 0.22.19 allows remote authenticated users to impersonate users via Constellation. In tokenMiddleware, the tunnel bypass returns before stripping attacker-supplied identity and role headers and before enforcing the AdminOnly gate. Exploitation requires an enrolled-device API key, tunnel access, an authentication-enabled proxy route, and an upstream that trusts the header; exposed admin-tier reads and writes then execute under a chosen identity.

The record

CVE
CVE-2026-49446
Published
Sep 15, 2026
Updated
Sep 15, 2026
Vendor
Beyond Cloud ltd.
Product
Cosmos Server
Classifications
CWE-290, CWE-285, T1078
Attack vector
adjacent
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 15, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 15, 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=< 0.22.19

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesauthenticated

What is affected?

Beyond Cloud ltd. · Cosmos Serverversion=< 0.22.19

Published CVSS scores

6.1GitHubCVSS:3.1/AV:A/AC:L/PR:H/UI:N/S:U/C:H/I:H/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)
Vectoradjacent
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-290Authentication Bypass by Spoofing
CWE-285Improper Authorization
T1078Valid Accounts

Public exploit references

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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