CVE-2026-48529Public exploitNetwork attack vectorHinoki check available

Cross-user content-filter bypass via singleton credentials

Published Jun 26, 2026 · Updated Jun 26, 2026

Improper access control in GitHub MCP Server 0.22.0 through 1.1.1 allows remote authenticated users to bypass content filtering. The process-global RepoAccessCache retains the first request’s GraphQL client, so later users’ access and visibility checks run with stale credentials. Exploitation requires multi-user HTTP mode with lockdown enabled and can expose unsanitized contributor content or interrupt checks after the first token expires.

CVSS severity6.0
Medium
EPSS probability0.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Improper access control in GitHub MCP Server 0.22.0 through 1.1.1 allows remote authenticated users to bypass content filtering. The process-global RepoAccessCache retains the first request’s GraphQL client, so later users’ access and visibility checks run with stale credentials. Exploitation requires multi-user HTTP mode with lockdown enabled and can expose unsanitized contributor content or interrupt checks after the first token expires.

The record

CVE
CVE-2026-48529
Published
Jun 26, 2026
Updated
Jun 26, 2026
Vendor
Twitter
Product
GitHub MCP Server
Classifications
CWE-284
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jun 26, 2026CVE publishedPublication date reported by the CVE source.
  2. Jun 26, 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=>= 0.22.0, < 1.1.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Twitter · GitHub MCP Serverversion=>= 0.22.0, < 1.1.2

Published CVSS scores

6.0GitHubCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:L

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-284Improper Access Control

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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