{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-77250", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-08-20T19:02:23.416Z", "datePublished": "2026-09-22T17:51:02.674Z", "dateUpdated": "2026-09-22T18:42:59.068Z"}, "containers": {"cna": {"title": "MCP Atlassian: OAuth fallback token storage writes plaintext access and refresh tokens with group-readable permissions", "problemTypes": [{"descriptions": [{"cweId": "CWE-312", "lang": "en", "description": "CWE-312: Cleartext Storage of Sensitive Information", "type": "CWE"}]}], "metrics": [{"cvssV3_1": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "NONE", "baseScore": 6.1, "baseSeverity": "MEDIUM", "confidentialityImpact": "HIGH", "integrityImpact": "LOW", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N", "version": "3.1"}}], "references": [{"name": "https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-g5xv-mhgm-v5f6", "tags": ["x_refsource_CONFIRM"], "url": "https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-g5xv-mhgm-v5f6"}, {"name": "https://github.com/sooperset/mcp-atlassian/pull/1448", "tags": ["x_refsource_MISC"], "url": "https://github.com/sooperset/mcp-atlassian/pull/1448"}, {"name": "https://github.com/sooperset/mcp-atlassian/commit/b041733473f95119dd539542a43c280737a8e460", "tags": ["x_refsource_MISC"], "url": "https://github.com/sooperset/mcp-atlassian/commit/b041733473f95119dd539542a43c280737a8e460"}, {"name": "https://github.com/sooperset/mcp-atlassian/releases/tag/v0.22.0", "tags": ["x_refsource_MISC"], "url": "https://github.com/sooperset/mcp-atlassian/releases/tag/v0.22.0"}], "affected": [{"vendor": "sooperset", "product": "mcp-atlassian", "versions": [{"version": "< 0.22.0", "status": "affected"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-09-22T17:51:02.674Z"}, "descriptions": [{"lang": "en", "value": "MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, OAuthConfig writes a plaintext fallback file containing access and refresh tokens under the user's .mcp-atlassian directory using process-default permissions. On systems with a permissive umask, same-group or other local users and processes can read the persisted tokens and reuse the associated Atlassian access. The advisory traces the vulnerable input and processing flow through OAuthConfig._save_tokens, ~/.mcp-atlassian/oauth-<client_id>.json, access_token, and refresh_token, which identify the affected entry points, controls, and code paths. This issue is fixed in version 0.22.0."}], "source": {"advisory": "GHSA-g5xv-mhgm-v5f6", "discovery": "UNKNOWN"}}, "adp": [{"references": [{"url": "https://github.com/sooperset/mcp-atlassian/security/advisories/GHSA-g5xv-mhgm-v5f6", "tags": ["exploit"]}], "metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2026-09-22T18:42:32.636268Z", "id": "CVE-2026-77250", "options": [{"Exploitation": "poc"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "role": "CISA Coordinator", "version": "2.0.3"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-09-22T18:42:59.068Z"}}]}}