{"answers":{"affected":"It affects 1 product.","exploited":"It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-77256 exists.","fix":"No fix has been published for CVE-2026-77256 yet. Limit exposure of the affected software until one is available.","what":"CVE-2026-77256 is a high-severity vulnerability in sooperset mcp-atlassian, published on 22 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-77256 and fix it if it is affected.\n\nWhat it is: CVE-2026-77256 is a high-severity vulnerability in sooperset mcp-atlassian, published on 22 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.\nExploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-77256 exists.\n\nAffected product: sooperset mcp-atlassian. No package-level version data is available, so check the vendor advisory linked from the reference page.\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2026-77256/ (Markdown: https://insights.sbomify.com/CVE-2026-77256/index.md)","id":"CVE-2026-77256","markdown":"https://insights.sbomify.com/CVE-2026-77256/index.md","name":"CVE-2026-77256","record":{"aliases":["GHSA-76pr-5669-3xf5"],"analysis":{"component_type":"developer_tool","fix_type":"upgrade","impacts":["data_read","account_takeover"],"network_reachable":"yes","non_default_config":false,"product_category":"MCP Atlassian server","requires_auth":"low_privilege","summary":"Local attackers can read world-readable OAuth token files to hijack Atlassian accounts due to insecure default file permissions.","user_interaction":"not_required","vuln_class":"information_disclosure"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[{"product":"mcp_atlassian","vendor":"mcp-atlassian"}],"cvss":{"score":8.3,"severity":"high","source":"cna","vector":"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","version":"4.0"},"cwes":[{"id":"CWE-732","name":"Incorrect Permission Assignment for Critical Resource"}],"description":"MCP Atlassian is a Model Context Protocol (MCP) server for Atlassian products (Confluence and Jira). Prior to 0.22.0, the plaintext OAuth fallback file containing refresh and access tokens is written with permissions inherited from the process umask. Under common or permissive configurations, other local users can read the backup and retain Atlassian access through the refresh token. The advisory traces the vulnerable input and processing flow through OAuthConfig._save_tokens_to_file, refresh_token, access_token, and umask, which identify the affected entry points, controls, and code paths. This issue is fixed in version 0.22.0.","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"weaponised"},"has_fix":false,"headline":"MCP Atlassian: OAuth refresh-token backup file is world-readable under default Unix umask","id":"CVE-2026-77256","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"information_disclosure","year":"2026"},"n_packages":0,"n_references":4,"next":{"headline":"MCP Atlassian: HTTP upload tools accept arbitrary server-local file paths","id":"CVE-2026-77257"},"packages":[],"prev":{"headline":"MCP Atlassian: Arbitrary File Read \u0026 Exfiltration (Confused Deputy) in JIRA update_issue","id":"CVE-2026-77255"},"products":["mcp-atlassian"],"published":"2026-09-22","related":[{"cvss_score":10,"headline":"[mcp-atlassian] Authentication bypass in HTTP transport: AtlassianOpaqueTokenVerifier accepts any non-empty token","id":"CVE-2026-77244","kev_date_added":null,"published":"2026-09-22"},{"cvss_score":9.1,"headline":"MCP Atlassian: Unauthenticated HTTP MCP requests can use globally configured Jira and Confluence credentials","id":"CVE-2026-77254","kev_date_added":null,"published":"2026-09-22"},{"cvss_score":9.1,"headline":"MCP Atlassian has an arbitrary file write leading to arbitrary code execution via unconstrained download_path in confluence_download_attachment","id":"CVE-2026-27825","kev_date_added":null,"published":"2026-03-10"},{"cvss_score":8.8,"headline":"MCP Atlassian: ENABLED_TOOLS / Toolset authorization bypass","id":"CVE-2026-77243","kev_date_added":null,"published":"2026-09-22"},{"cvss_score":8.8,"headline":"MCP Atlassian: SSRF Protection Bypass","id":"CVE-2026-77274","kev_date_added":null,"published":"2026-09-22"},{"cvss_score":8.6,"headline":"MCP Atlassian: Unauthenticated arbitrary local file read via upload_attachment file_path, chained with missing auth on streamable-http transport","id":"CVE-2026-77248","kev_date_added":null,"published":"2026-09-22"},{"cvss_score":8.6,"headline":"MCP Atlassian: Arbitrary File Read \u0026 Exfiltration (Confused Deputy) in JIRA update_issue","id":"CVE-2026-77255","kev_date_added":null,"published":"2026-09-22"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"US public information, NVD API terms","name":"NVD"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"no","exploitation":"poc","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-09-22","vendors":["sooperset"]},"summary":"Local attackers can read world-readable OAuth token files to hijack Atlassian accounts due to insecure default file permissions.","url":"https://insights.sbomify.com/CVE-2026-77256/"}