CVE-2026-77258High· 7.7▾ MidnightPoC available

MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira)

▾ Midnight zone — Critical, or high with PoC / in-the-wild

Depth score54/ 100 · Moderate

impact 42.4 · likelihood 0.1 · exploitation 12

⚡ Agent-ready:Raw markdown ↗JSON ↗

Proof of concept

A public proof-of-concept already exists for this vulnerability — see Exploit availability below.

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Published

Sep 22, 2026

Updated

Sep 26, 2026

CVSS

7.7

Vendor

sooperset

Product

mcp-atlassian

CWE

CWE-22

Depth score

54 · Moderate

EPSS

0.37% · p31

Platforms

—

Source

NVD

Vector

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

CISA SSVC

decided 2026-09-25

Exploitation: poc
Automatable: no
Technical impact: partial

Stakeholder-Specific Vulnerability Categorization from CISA's ADP record at CVE.org: whether exploitation is observed, whether an attack can be automated, and how much of the system is at stake.

EPSS history

Exploit-prediction probability, daily snapshots since Sep 23.

0.5% → 0.4%▼ 0.1%

Timeline

Disclosure to exploitation, from the record and what we observed since indexing it.

4 events · 4 days

Sep 22, 2026Published
Disclosed via NVD
Sep 23, 2026EPSS first tracked
0.5%
Sep 26, 2026Record revised
Last analysed / modified upstream
Sep 26, 2026Public exploit observed
Exploit / PoC code exists

sooperset CWE-22 #nvd #cve.org #exploit-available #ghsa #pip #osv

Affected

mcp-atlassian < 0.22.0

Patched in

mcp-atlassian 0.22.0

Full technical detail▾

Overview

MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, upload_attachment in src/mcp_atlassian/confluence/attachments.py accepts a caller-controlled file_path and opens the selected server-local file without restricting it to the workspace. A permitted Confluence MCP caller can upload the file as an attachment and disclose data readable by the server process. This issue is fixed in version 0.22.0.

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

Package advisory (CVE-2026-77258)

Affected packages:

mcp-atlassian < 0.22.0

Patched in:

mcp-atlassian 0.22.0

Source: https://github.com/advisories/GHSA-93xw-j965-9mx3

References

Change history

Field changes observed since this record was first indexed.

Sep 26, 2026Public exploit / PoC published

Related vulnerabilities

Connected by shared product, vendor, weakness, or advisory.

#nvd#cve.org#exploit-available#ghsa#pip#osv

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