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CVE-2026-77260Proof of concept (PoC) published · CISA

MCP Atlassian: Arbitrary local file READ via unconstrained file_path in upload_attachment (Confluence + Jira)

CVSS score

8.3

EPSS probability

%0.3

Risk score

0.0

Published

25 d ago

OverviewPublic Exploits (0)NewsroomVulnerability Timeline
Official patch verified

Etkilenen ürün ve sürüm için yayımlanan güvenlik güncellemesini uygulayın.

Impact on My Inventory

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Vulnerability description

DayBreach CVE AI Research

CVE-2026-77260 has vendor, distribution, patch and security-source records on file. We can compare them and prepare an explanation linked to the evidence.

MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, the Confluence and Jira upload_attachment implementations accept an unconstrained file_path and open the referenced server-local file. A permitted MCP caller can upload sensitive host files to an Atlassian destination and then retrieve their contents. The advisory traces the vulnerable input and processing flow through upload_attachment, file_path, and CVE-2026-27825, which identify the affected entry points, controls, and code paths. This issue is fixed in version 0.22.0.

IMPACT: Affected Products and Software

Affected Products

The following products are affected by CVE-2026-77260 vulnerability. Where our threat engine knows the exact affected versions, they are listed below.

IDVENDORPRODUCTACTION
1soopersetmcp-atlassian View
2mcp-atlassianmcp atlassian View
3pypimcp-atlassian View
Total affected vendors: 3|Products: 3

RED HAT CSAF/VEX: Product Impact Check

Red Hat has not yet published a CSAF/VEX impact record for this CVE. This does not mean “not affected”.

SCORING: CVSS from Multiple Sources

CVSS Scores

The Common Vulnerability Scoring System is a standardised framework for assessing the severity of vulnerabilities in software and systems. We collect and display CVSS scores from several sources for each CVE.

SCOREVERSIONSEVERITYVECTORSOURCE
8.3CVSS V4_0HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:NCVE CNA
8.3CVSS 4.0—Vector not publishedGitHub Advisory
8.3CVSS V40HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:XNVD
7.5CVSS V31HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:NNVD

Patch and Remediation Guide

Solution & Remediation Advisory

Patch verified

3 doğrulanmış yama veya düzeltilmiş sürüm kanıtı bulundu.

osvmcp-atlassian0.22.0

OSV düzeltilmiş sürüm: 0.22.0

nvd

NVD tarafından Patch olarak etiketlenmiş referans

Open source
nvd

NVD tarafından Patch olarak etiketlenmiş referans

Open source
Confirm the affected product and version against the source evidence above.
Restrict access to internet-facing services and apply network segmentation.
Apply the official update named in the evidence only to the matching product and version.
Monitor server logs and network endpoints for signs of anomalous execution.

Public exploit and active exploitation status

Verified exploit intelligence

No verified public PoC, exploit repository or Metasploit module has been found for this CVE yet.

Weakness Classification and Attack Patterns (CWE & CAPEC)

CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorises the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-77260 is associated with the following CWEs:

CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-77260 weaknesses.

CAPEC-66: SQL InjectionCAPEC-126: Path TraversalCAPEC-28: OS Command Injection

Attack Vector and Accessibility

ExposureAğ üzerinden
PermissionsLow
UserGerekmiyor

Official Sources and Advisories

https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-f4p7-qx46-wc5jvendor-advisoryhttps://github.com/sooperset/mcp-atlassian/pull/1448vendor-advisoryhttps://github.com/sooperset/mcp-atlassian/commit/b041733473f95119dd539542a43c280737a8e460vendor-advisoryhttps://github.com/sooperset/mcp-atlassian/releases/tag/v0.22.0vendor-advisoryhttps://nvd.nist.gov/vuln/detail/CVE-2026-77260vendor-advisoryhttps://github.com/advisories/GHSA-f4p7-qx46-wc5jvendor-advisoryhttps://github.com/sooperset/mcp-atlassianvendor-advisoryhttps://pypi.org/project/mcp-atlassianvendor-advisory

CVSS Vector Radar Chart

8.3 / 10
Attack VectorNetworkComplexityLowPrivilegesLowUser Interact.NoneConfidentialityLowIntegrityNoneAvailabilityNone

Vulnerability Scoring Details

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N
Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredLow privileges
User InteractionNone required
Confidentiality (Gizlilik)Low
Integrity (Bütünlük)None
Availability (Erişilebilirlik)None

Yama doğrulandı

3 doğrulanmış yama veya düzeltilmiş sürüm kanıtı bulundu.

Follow the vendor

S
sooperset logo
sooperset
M
mcp-atlassian logo
mcp-atlassian
P
pypi logo
pypi

Weakness Type (CWE & CAPEC)

CWE-22

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