{"items":[{"id":"NVI-00017714","kind":"vulnerability","title":"MCP Atlassian: DNS-rebinding TOCTOU bypass of the SSRF fix (CVE-2026-27826)","revision":1,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-489g-7rxv-6c8q"],"plain_summary":"GitHub lists this reviewed advisory for mcp-atlassian. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.","review_status":"source_listed","control_topics":[],"public_actions":[{"summary":"Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.","source_ids":["sr-4deba040e40d4d16749662c53952fd4b"],"action_type":"investigate","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null}],"schema_version":"1.1.0","source_metrics":[{"kind":"CVSS","as_of":"2026-07-10T18:01:22.000Z","value":"6.5 medium","meaning":"GitHub source severity; exploitability and local consequence require separate evidence.","source_id":"sr-4deba040e40d4d16749662c53952fd4b"}],"why_it_matters":"Published affected context helps an owner decide what evidence to gather. This report has not examined your application.","related_sources":[{"id":"sr-4deba040e40d4d16749662c53952fd4b","url":"https://github.com/advisories/GHSA-489g-7rxv-6c8q","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-489g-7rxv-6c8q","publisher":"GitHub Advisory Database","observed_at":"2026-11-04T23:34:12.429Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-4deba040e40d4d16749662c53952fd4b"],"technology":"mcp-atlassian","known_exclusions":[],"conditions_summary":"### Summary\nGHSA-7r34-79r5-rcc9's fix added `validate_url_for_ssrf`, which resolves the attacker-controlled `X-Atlassian-{Jira,Confluence}-Url` header host **once at middleware time** and trusts the result. But the outbound request is later built with the **raw hostname** and **re-resolves at connect time with no IP pinning**. An attacker-controlled rebinding DNS name returns a public IP on the guard's lookup (validation passes) and `169.254.169.254` / an internal IP on the request's lookup (the socket connects there) → unauthenticated SSRF to cloud metadata / internal services on the **patched** build.\n\n### Relationship to CVE-2026-27826 / GHSA-7r34-79r5-rcc9 (incomplete fix — please read first)\nThis is an **incomplete-fix sibling** of the published `GHSA-7r34-79r5-rcc9` (the `X-Atlassian-*-Url` header SSRF). That fix (PR #986/#1005) added a single middleware-time resolve + allowlist DNS-skip, but **does not pin the validated IP to the connection** — the fetcher re-resolves the raw hostname at connect time, so the documented SSRF mitigation is incomplete against DNS-rebinding. The other advisory `GHSA-xjgw-4wvw-rgm4` (file-write) is unrelated. Verified live (2026-06-27): neither a","public_affected_ranges":["< 0.22.0"]}],"null_published_at":"2026-11-05T19:10:21.456Z","source_updated_at":"2026-07-10T18:01:22.000Z","source_disclosed_at":"2026-07-10T18:01:22.000Z","is_synthetic_fixture":false,"null_last_reviewed_at":null,"public_change_summary":"First indexed by Null; source disclosure date is shown separately.","null_first_observed_at":"2026-11-04T23:34:12.429Z"}],"next_cursor":null,"snapshot_revision":"42594"}