CVE-2026-77258Public exploitNetwork attack vectorHinoki check available

File exfiltration via unconstrained attachment path

Published Sep 22, 2026 · Updated Sep 22, 2026

Path traversal in MCP Atlassian before 0.22.0 allows remote authenticated users to read server-local files through a Confluence tool call. The upload_attachment method resolves a caller-controlled file_path and opens it without validate_safe_path, allowing paths outside the workspace. Access requires permission to invoke the Confluence MCP tool and upload attachments, and exposure is limited to files readable by the server process.

CVSS severity7.7
High
EPSS probability0.34%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Path traversal in MCP Atlassian before 0.22.0 allows remote authenticated users to read server-local files through a Confluence tool call. The upload_attachment method resolves a caller-controlled file_path and opens it without validate_safe_path, allowing paths outside the workspace. Access requires permission to invoke the Confluence MCP tool and upload attachments, and exposure is limited to files readable by the server process.

The record

CVE
CVE-2026-77258
Published
Sep 22, 2026
Updated
Sep 22, 2026
Vendor
sooperset
Product
MCP Atlassian
Classifications
CWE-22, T1005, T1567
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

7.7GitHubCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/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-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
T1005Data from Local System
T1567Exfiltration Over Web Service

Public exploit references

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

Technologies

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