CVE-2026-77271

MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to…

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 tracked as CVE-2026-27825. This issue is fixed in version 0.22.0.

Vendor: mcp-atlassian
Product: mcp atlassian
CVSS 3.1: 8.8 (high), scored by NVD (primary)CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CVSS 4.0: 8.3 (high), scored by security-advisories@github.comCVSS: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:X
CWE: CWE-22, CWE-94
Published: 2026-09-22
NVD modified: 2026-09-28
NVD status: Analyzed

Not in the CISA KEV catalogue at the last update.

EPSS

0.53% chance of exploitation in the next 30 days (percentile 43rd)

FIRST EPSS, updated 17 Oct 2026. About EPSS

CVSS is severity, EPSS is likelihood, KEV means already exploited. EPSS is a statistical probability, not a certainty: a low score does not make a bug safe, and a high one does not prove it is being exploited.

References

github.com (Patch)
github.com (Issue Tracking, Patch)
github.com (Release Notes)

Data last updated 18 Oct 2026. Sources: NVD API 2.0, FIRST EPSS. Links: NVD, CISA KEV. Metadata only. ThreatWire does not host exploit code.