{"items":[{"id":"NVI-00017534","kind":"vulnerability","title":"Concourse login flow has an open redirect issue","revision":1,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-8w27-c4vc-88q9","CVE-2026-49826"],"plain_summary":"GitHub lists this reviewed advisory for github.com/concourse/concourse. 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-160973ad2b8f6606bd19a287f0389709"],"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":[],"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-160973ad2b8f6606bd19a287f0389709","url":"https://github.com/advisories/GHSA-8w27-c4vc-88q9","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-8w27-c4vc-88q9","publisher":"GitHub Advisory Database","observed_at":"2026-11-05T03:49:14.191Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-160973ad2b8f6606bd19a287f0389709"],"technology":"github.com/concourse/concourse","known_exclusions":[],"conditions_summary":"### Impact\n\nAn attacker is able to craft and send a user a URL that will redirect the user from the Concourse web server to any other site. This could be used in a phishing attack to steal user's credentials.\n\n### Patches\n\nThis has been fixed in 8.2.3\n\n### Workarounds\n\nNone.\n\n### Exploit\n\nVulnerable code was in: https://github.com/concourse/concourse/blob/ea7b812e3a88fdd070f0faece874e8a2d4fbb31c/skymarshal/skyserver/skyserver.go#L162-L170\n\nThe issue stems from the underlying processing logic of Go's `url` package. Normally, `ParseRequestURI()` will eventually reach an internal `url.setPath()` function, where the URL will be decoded. However, if `RawPath` is not empty and `validEncoded(RawPath)` is true, and the decoded result equals `Path`, then return `RawPath` as is; otherwise, escape `Path` again, i.e., decode it again.\n\nIn other words, if the URL contains dangerous characters that should be escaped, such as backslashes (`\\`), then an extra decoding step will be performed. Therefore, `/%2Fexample.com` will be parsed as `//example.com`.\n\nOn vulnerable versions of Concourse, add `/sky/login?redirect_uri=/%252Fexample.com/\\` to your Concourse external URL, login as usual, and you s","public_affected_ranges":["< 1.6.1-0.20260526150512-ac60be5f0435"]}],"null_published_at":"2026-11-05T19:10:21.406Z","source_updated_at":"2026-07-01T19:01:17.000Z","source_disclosed_at":"2026-07-01T19:01:16.000Z","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":"2026-11-05T03:49:14.191Z"}],"next_cursor":null,"snapshot_revision":"42594"}