CVE-2026-77271: MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira)

Q: How do I fix CVE-2026-77271?

mcp atlassian: upgrade to 0.22.0. Exact commands for each OS are on this page.

Q: Is CVE-2026-77271 being exploited?

CVE-2026-77271 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-77271 affect?

CVE-2026-77271 affects mcp atlassian. Severity is high (CVSS 8.8). MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, validate_safe_path defaults its base directory to os.getcwd(), and affected Confluence attachment call sites omit base_dir

Q: How urgent is CVE-2026-77271?

Priority 48/100. High severity; Public exploit reference

This month

HIGH 8.8UPGRADE

CVE-2026-77271 is a high-severity flaw (CVSS 8.8) affecting mcp atlassian. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, validate_safe_path defaults its base directory to os.getcwd(), and affected Confluence attachment call sites omit base_dir, allowing attacker-selected writes within the working directory. This Python module overwrite can provide code execution when the application later imports the modified module, bypassing the remediation tracke

Why this priority

High severity
Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	8.8 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.6% (top 52%)
CISA exploited list	No
Weakness	CWE-22, CWE-94
Published	2026-09-22
Last modified	2026-09-28

Publisher (CNA): GitHub, Inc. · Vendor: mcp-atlassian

Last updated 2026-09-28 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-09-22 18:17 UTCPublished CVE record published
2026-09-28 13:45 UTCUpdated Record last modified

mcp-atlassian mcp atlassian UPGRADE

Affected: < 0.22.0

Fixed in: 0.22.0

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy mcp-atlassian || rpm -q mcp-atlassian || mcp-atlassian --version

2. UPGRADE to 0.22.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade mcp-atlassian

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade mcp-atlassian

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-77271?

mcp atlassian: upgrade to 0.22.0. Exact commands for each OS are on this page.

Is CVE-2026-77271 being exploited?

CVE-2026-77271 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-77271 affect?

CVE-2026-77271 affects mcp atlassian. Severity is high (CVSS 8.8). MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, validate_safe_path defaults its base directory to os.getcwd(), and affected Confluence attachment call sites omit base_dir

How urgent is CVE-2026-77271?

Priority 48/100. High severity; Public exploit reference

Software pages

Python vulnerabilities · Atlassian Confluence vulnerabilities · Atlassian Jira vulnerabilities

Related CVEs

CVE-2026-77265 MEDIUM 5.9 UPGRADE MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira)
CVE-2026-77267 MEDIUM 6.5 UPGRADE MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira)
CVE-2026-77249 MEDIUM 5.3 UPGRADE MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira)
CVE-2026-77257 MEDIUM 6.5 UPGRADE MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira)
CVE-2026-77262 HIGH 8.6 UPGRADE MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira)

References

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