{"items":[{"id":"NVI-00011690","kind":"vulnerability","title":"Vikunja: Link-share token can enumerate users through the v2 API","revision":3,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected.","NVD lastModified does not establish freshness of every associated CPE record."],"lifecycle":"active","identifiers":["GHSA-vfxw-3x8p-2vjr","CVE-2026-91981"],"plain_summary":"GitHub lists this reviewed advisory for code.vikunja.io/api. 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-4aec4a160c20765edb1c127ae633f029"],"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":"2026-09-21T19:17:16.220Z","value":"4.3 MEDIUM (3.1)","meaning":"disclosure@vulncheck.com severity; no combined Null risk score.","source_id":"sr-7b03aba83cb91fbd24af065588ee4358"},{"kind":"CVSS","as_of":"2026-09-21T19:17:16.220Z","value":"5.3 MEDIUM (4.0)","meaning":"disclosure@vulncheck.com severity; no combined Null risk score.","source_id":"sr-7b03aba83cb91fbd24af065588ee4358"},{"kind":"EPSS","as_of":"2026-10-31T12:00:27.000Z","value":"0.306%","meaning":"FIRST EPSS model v2026.06.15; exploitation probability over 30 days, percentile 0.2345. Missing scores are unknown.","source_id":"sr-4aec4a160c20765edb1c127ae633f029"}],"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-0227ae29ca00b3ea5b8b97ca2d00e56b","url":"https://github.com/advisories/GHSA-vfxw-3x8p-2vjr","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-vfxw-3x8p-2vjr","publisher":"GitHub Advisory Database","observed_at":"2026-10-31T23:14:22.124Z"},{"id":"sr-7b03aba83cb91fbd24af065588ee4358","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-91981","basis":"official_catalog","notes":"This product uses data from the NVD API but is not endorsed or certified by the NVD.","title":"CVE-2026-91981","publisher":"NIST National Vulnerability Database","observed_at":"2026-11-04T09:59:50.242Z"},{"id":"sr-4aec4a160c20765edb1c127ae633f029","url":"https://www.first.org/epss/data.html","basis":"official_catalog","notes":"FIRST EPSS; probability of exploitation in the next 30 days, not local compromise. Dataset date/model retained; FIRST services terms apply.","title":"CVE-2026-91981","publisher":"FIRST EPSS","observed_at":"2026-11-01T01:39:43.089Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-0227ae29ca00b3ea5b8b97ca2d00e56b"],"technology":"code.vikunja.io/api","known_exclusions":[],"conditions_summary":"### Summary\nA link-share token, the credential you hand out to let someone view a shared project, can call the v2 user-search endpoints, which it was never meant to reach. The v1 versions of the same endpoints correctly reject link-share tokens; the v2 versions don't. As a result, anyone with a share link can list every member of the shared project (and its parent projects), and can test whether any username exists anywhere on the instance.\n\n### Details\nTwo endpoints are affected:\n\n`GET /api/v2/projects/{id}/users/search` only checks project.CanRead, which a link share satisfies on its own project. With no parameter it returns the full user list, walking up the parent-project chain.\n`GET /api/v2/users?q=` is a global search. It needs a query term, but any term works as an existence oracle: a hit confirms the username exists somewhere on the instance and returns the display name.\n\nEmails are correctly stripped from these responses, so the exposure is limited to identities (usernames and display names), but that's still an instance-wide directory that a share-link holder should never see.\n\nThe fix is to resolve the caller with GetFromAuth in both handlers, so link-share tokens ","public_affected_ranges":["<= 2.5.0"]}],"null_published_at":"2026-11-08T15:11:49.362Z","source_updated_at":"2026-10-09T20:52:41.000Z","source_disclosed_at":"2026-10-09T20:52:39.000Z","is_synthetic_fixture":false,"null_last_reviewed_at":null,"public_change_summary":"Source facts changed; compare the preserved prior revision.","null_first_observed_at":"2026-10-31T23:14:22.124Z"},{"id":"NVI-00011690","kind":"vulnerability","title":"Vikunja: Link-share token can enumerate users through the v2 API","revision":2,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-vfxw-3x8p-2vjr","CVE-2026-91981"],"plain_summary":"GitHub lists this reviewed advisory for code.vikunja.io/api. 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-4aec4a160c20765edb1c127ae633f029"],"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":"EPSS","as_of":"2026-10-31T12:00:27.000Z","value":"0.306%","meaning":"FIRST EPSS model v2026.06.15; exploitation probability over 30 days, percentile 0.2345. Missing scores are unknown.","source_id":"sr-4aec4a160c20765edb1c127ae633f029"}],"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-0227ae29ca00b3ea5b8b97ca2d00e56b","url":"https://github.com/advisories/GHSA-vfxw-3x8p-2vjr","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-vfxw-3x8p-2vjr","publisher":"GitHub Advisory Database","observed_at":"2026-10-31T23:14:22.124Z"},{"id":"sr-4aec4a160c20765edb1c127ae633f029","url":"https://www.first.org/epss/data.html","basis":"official_catalog","notes":"FIRST EPSS; probability of exploitation in the next 30 days, not local compromise. Dataset date/model retained; FIRST services terms apply.","title":"CVE-2026-91981","publisher":"FIRST EPSS","observed_at":"2026-11-01T01:39:43.089Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-0227ae29ca00b3ea5b8b97ca2d00e56b"],"technology":"code.vikunja.io/api","known_exclusions":[],"conditions_summary":"### Summary\nA link-share token, the credential you hand out to let someone view a shared project, can call the v2 user-search endpoints, which it was never meant to reach. The v1 versions of the same endpoints correctly reject link-share tokens; the v2 versions don't. As a result, anyone with a share link can list every member of the shared project (and its parent projects), and can test whether any username exists anywhere on the instance.\n\n### Details\nTwo endpoints are affected:\n\n`GET /api/v2/projects/{id}/users/search` only checks project.CanRead, which a link share satisfies on its own project. With no parameter it returns the full user list, walking up the parent-project chain.\n`GET /api/v2/users?q=` is a global search. It needs a query term, but any term works as an existence oracle: a hit confirms the username exists somewhere on the instance and returns the display name.\n\nEmails are correctly stripped from these responses, so the exposure is limited to identities (usernames and display names), but that's still an instance-wide directory that a share-link holder should never see.\n\nThe fix is to resolve the caller with GetFromAuth in both handlers, so link-share tokens ","public_affected_ranges":["<= 2.5.0"]}],"null_published_at":"2026-11-01T22:58:19.124Z","source_updated_at":"2026-10-09T20:52:41.000Z","source_disclosed_at":"2026-10-09T20:52:39.000Z","is_synthetic_fixture":false,"null_last_reviewed_at":null,"public_change_summary":"Dated EPSS estimate updated; this is not a new disclosure or proof of exploitation.","null_first_observed_at":"2026-10-31T23:14:22.124Z"},{"id":"NVI-00011690","kind":"vulnerability","title":"Vikunja: Link-share token can enumerate users through the v2 API","revision":1,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-vfxw-3x8p-2vjr","CVE-2026-91981"],"plain_summary":"GitHub lists this reviewed advisory for code.vikunja.io/api. 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-0227ae29ca00b3ea5b8b97ca2d00e56b"],"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-0227ae29ca00b3ea5b8b97ca2d00e56b","url":"https://github.com/advisories/GHSA-vfxw-3x8p-2vjr","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-vfxw-3x8p-2vjr","publisher":"GitHub Advisory Database","observed_at":"2026-10-31T23:14:22.124Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-0227ae29ca00b3ea5b8b97ca2d00e56b"],"technology":"code.vikunja.io/api","known_exclusions":[],"conditions_summary":"### Summary\nA link-share token, the credential you hand out to let someone view a shared project, can call the v2 user-search endpoints, which it was never meant to reach. The v1 versions of the same endpoints correctly reject link-share tokens; the v2 versions don't. As a result, anyone with a share link can list every member of the shared project (and its parent projects), and can test whether any username exists anywhere on the instance.\n\n### Details\nTwo endpoints are affected:\n\n`GET /api/v2/projects/{id}/users/search` only checks project.CanRead, which a link share satisfies on its own project. With no parameter it returns the full user list, walking up the parent-project chain.\n`GET /api/v2/users?q=` is a global search. It needs a query term, but any term works as an existence oracle: a hit confirms the username exists somewhere on the instance and returns the display name.\n\nEmails are correctly stripped from these responses, so the exposure is limited to identities (usernames and display names), but that's still an instance-wide directory that a share-link holder should never see.\n\nThe fix is to resolve the caller with GetFromAuth in both handlers, so link-share tokens ","public_affected_ranges":["<= 2.5.0"]}],"null_published_at":"2026-11-01T01:03:56.585Z","source_updated_at":"2026-10-09T20:52:41.000Z","source_disclosed_at":"2026-10-09T20:52:39.000Z","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":"2026-10-31T23:14:22.124Z"}],"next_cursor":null,"snapshot_revision":"42594"}