CVE-2026-77252Public exploitNetwork attack vectorHinoki check available

Authenticated content disclosure via replaceable search allowlists

Published Sep 22, 2026 · Updated Sep 22, 2026

Improper access control in MCP Atlassian before 0.22.0 allows remote authenticated users to read unauthorized Jira or Confluence content. SearchMixin.search_issues and SearchMixin.search let caller-supplied filter arguments replace configured allowlists, and suppress those allowlists when JQL or CQL contains a project or space clause. Exploitation requires an MCP caller plus configured Atlassian credentials that can access content beyond the administrator's project or space filter.

CVSS severity6.5
Medium
EPSS probability0.30%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Improper access control in MCP Atlassian before 0.22.0 allows remote authenticated users to read unauthorized Jira or Confluence content. SearchMixin.search_issues and SearchMixin.search let caller-supplied filter arguments replace configured allowlists, and suppress those allowlists when JQL or CQL contains a project or space clause. Exploitation requires an MCP caller plus configured Atlassian credentials that can access content beyond the administrator's project or space filter.

The record

CVE
CVE-2026-77252
Published
Sep 22, 2026
Updated
Sep 22, 2026
Vendor
sooperset
Product
MCP Atlassian
Classifications
CWE-284, T1213
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 22, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 22, 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

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

sooperset · MCP Atlassianversion=< 0.22.0

Published CVSS scores

6.5GitHub Security AdvisoryCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/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.

Activity data is delayed. The latest report is Sep 28, 2026.

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

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 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
T1213Data from Information Repositories

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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