Sign in Sign up
JA · EN · FR
SecPulse
Categories
CVE-2026-77258 high CVSS 7.7

Path Traversal in mcp-atlassian (CVE-2026-77258)

Summary

Path traversal in mcp-atlassian (CVE-2026-77258). Confidential information can be exposed externally. Exploitable via upload_attachment. Mitigation: upgrade to 0.22.0 or later.

Original description

The description as published by the source.

Summary

The upload_attachment method in confluence/attachments.py reads and uploads arbitrary local files to Confluence without calling validate_safe_path(). Both download methods (download_attachment at line 223, download_content_attachments at line 272) correctly call validate_safe_path() before writing files, but the upload path at lines 35-79 skips this check entirely.

An AI agent connected via MCP (or an attacker influencing that agent through prompt injection) can read any file on the host and exfiltrate it by uploading it as a Confluence page attachment.

Vulnerable Code

File: src/mcp_atlassian/confluence/attachments.py, lines 62-79

# No validate_safe_path() call anywhere in this method
if not os.path.isabs(file_path):
    file_path = os.path.abspath(file_path)

if not os.path.exists(file_path):
    return {"success": False, "error": f"File not found: {file_path}"}

filename = os.path.basename(file_path)
attachment = self._upload_attachment_direct(
    content_id, file_path, filename, comment, minor_edit
)

The validate_safe_path function is already imported at line 9 of the same file, and used in the download methods. It was just not added to the upload path.

Proof of Concept

Tested with mcp-atlassian 0.21.1 on Python 3.11 (EC2, Amazon Linux 2023).

import inspect
from mcp_atlassian.confluence.attachments import AttachmentsMixin

# Confirm: no validate_safe_path in upload
source = inspect.getsource(AttachmentsMixi…

Source: NIST National Vulnerability Database NVD GitHub Advisory

Auto-generated summary

Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.

A vulnerability tracked as CVE-2026-77258 has been found in mcp-atlassian.
Attackers can target a specific entry point like upload_attachment over the network to misuse the product.
Confidential information can be exposed externally. CVSS score: 7.7/10.
What to do: upgrade mcp-atlassian to 0.22.0 or later.
If unsure, ask your IT team or search "mcp-atlassian CVE-2026-77258" on the vendor's site.

CVE-2026-77258 (mcp-atlassian) — CWE-22 / CVSS v3 7.7
Attack vector: remote (network-reachable) / no user interaction
Attack surface: upload_attachment / download_attachment / download_content_attachments / validate_safe_path
Patched: 0.22.0 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.

❓ What is the problem

Path traversal (CWE-22) exists in mcp-atlassian. Attackers reach the vulnerable code path via upload_attachment.

📍 Affected scope

Check the vendor advisory for the affected versions of mcp-atlassian. Attack surface: upload_attachment / download_attachment / download_content_attachments / validate_safe_path.

🔥 Severity

Severity: High (CVSS 7.7/10). Confidential information can be exposed externally.

🔧 How to fix

Update to 0.22.0.

🛡️ Workaround

Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.

🔍 Detection

Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'mcp-atlassian' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.

Response actions

Concrete steps and command examples for SOC/SRE teams to execute in order

  1. 1
    Identify exposure identify 
    grep -r 'mcp-atlassian' . | grep -v node_modules

    リポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で mcp-atlassian を grep し、稼働しているサービス・バージョンを把握する。

  2. 2
    Apply patch patch 
    Upgrade mcp-atlassian to 0.22.0

    ステージング環境で 0.22.0 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。

  3. 3
    Post-deployment verification verify 
    Confirm patched version is live in production

    パッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。

Affected packages

pip mcp-atlassian
[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.22.0"}]}]

References

We use cookies for analytics and ad measurement. This setting applies to all Game co., Ltd. sites. Details