Vulnerability-Lookup

BDU:2026-08694 (CVE-2026-45156)

Vulnerability from fstec – Published: 2026-06-25 – Updated: 2026-06-25 – View on bdu.fstec.ru Exploit publicly available Fixed

Title

Уязвимость модуля авторизации User OIDC облачного программного обеспечения для создания и использования хранилища данных Nextcloud, позволяющая нарушителю повысить свои привилегии

Summary

Уязвимость модуля авторизации User OIDC облачного программного обеспечения для создания и использования хранилища данных Nextcloud связана с недостатками процедуры аутентификации. Эксплуатация уязвимости может позволить нарушителю, действующему удаленно, повысить свои привилегии

Severity

9.4 (High) CVSS 2.0


                      
                        AV:N/AC:L/Au:N/C:C/I:C/A:N

8.1 (High) CVSS 3.1


                      
                        CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N

Class

Architecture vulnerability

Status

Confirmed by the vendor

Exploitation

Authentication bypass

Consequences

Privilege escalation

Incidents

Being clarified

Remediation

Software update

CWE

CWE-287 - Неправильная аутентификация

Aliases

CVE-2026-45156, GHSA-QQGV-FQWP-MJPP

References

3 references

URL
https://github.com/cybertechajju/CVE-2026-45156-POC
https://github.com/nextcloud/security-advisories/security/advisories/GHSA-qqgv-…
https://hackerone.com/reports/3489490

Impacted products

1 product from 1 vendor

Vendors

Nextcloud GmbH

Products

Nextcloud

Versions

от 0.3.0 до 3.1.0 (Nextcloud), от 5.0.0 до 5.1.0 (Nextcloud), от 6.0.0 до 6.4.0 (Nextcloud), до 4.1.0 (Nextcloud), до 8.3.0 (Nextcloud)

Product types

Application software

Mitigations

Использрвание рекомендаций производителя: https://github.com/nextcloud/security-advisories/security/advisories/GHSA-qqgv-fqwp-mjpp Компенсирующие меры: - отключение функции ID4me в приложении Nextcloud User OIDC; - использование средств межсетевого экранирования и блокировка маршрутов ID4me уровня веб-приложений (WAF) для сетевого трафика; - использование средств антивирусной защиты для проверки файлов, полученных из недоверенных источников; - минимизация пользовательских привилегий; - использование только доверенных OIDC/ID4me-провайдеров для идентификации; - включение многофакторной аутентификации для привилегированных учетных записей; - отключение/удаление неиспользуемых учётных записей пользователей; - ограничение доступа из внешних сетей (Интернет).

JSON

To clipboard

{
  "CVSS 2.0": "AV:N/AC:L/Au:N/C:C/I:C/A:N",
  "CVSS 3.0": "AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N",
  "CVSS 4.0": null,
  "remediation_\u0418\u0434\u0435\u043d\u0442\u0438\u0444\u0438\u043a\u0430\u0442\u043e\u0440": null,
  "remediation_\u041d\u0430\u0438\u043c\u0435\u043d\u043e\u0432\u0430\u043d\u0438\u0435": null,
  "\u0412\u0435\u043d\u0434\u043e\u0440 \u041f\u041e": "Nextcloud GmbH",
  "\u0412\u0435\u0440\u0441\u0438\u044f \u041f\u041e": "\u043e\u0442 0.3.0 \u0434\u043e 3.1.0 (Nextcloud), \u043e\u0442 5.0.0 \u0434\u043e 5.1.0 (Nextcloud), \u043e\u0442 6.0.0 \u0434\u043e 6.4.0 (Nextcloud), \u0434\u043e 4.1.0 (Nextcloud), \u0434\u043e 8.3.0 (Nextcloud)",
  "\u0412\u043e\u0437\u043c\u043e\u0436\u043d\u044b\u0435 \u043c\u0435\u0440\u044b \u043f\u043e \u0443\u0441\u0442\u0440\u0430\u043d\u0435\u043d\u0438\u044e": "\u0418\u0441\u043f\u043e\u043b\u044c\u0437\u0440\u0432\u0430\u043d\u0438\u0435 \u0440\u0435\u043a\u043e\u043c\u0435\u043d\u0434\u0430\u0446\u0438\u0439 \u043f\u0440\u043e\u0438\u0437\u0432\u043e\u0434\u0438\u0442\u0435\u043b\u044f:\n\nhttps://github.com/nextcloud/security-advisories/security/advisories/GHSA-qqgv-fqwp-mjpp\n\n\n\n\u041a\u043e\u043c\u043f\u0435\u043d\u0441\u0438\u0440\u0443\u044e\u0449\u0438\u0435 \u043c\u0435\u0440\u044b:\n\n- \u043e\u0442\u043a\u043b\u044e\u0447\u0435\u043d\u0438\u0435 \u0444\u0443\u043d\u043a\u0446\u0438\u0438 ID4me \u0432 \u043f\u0440\u0438\u043b\u043e\u0436\u0435\u043d\u0438\u0438 Nextcloud User OIDC;\n\n- \u0438\u0441\u043f\u043e\u043b\u044c\u0437\u043e\u0432\u0430\u043d\u0438\u0435 \u0441\u0440\u0435\u0434\u0441\u0442\u0432 \u043c\u0435\u0436\u0441\u0435\u0442\u0435\u0432\u043e\u0433\u043e \u044d\u043a\u0440\u0430\u043d\u0438\u0440\u043e\u0432\u0430\u043d\u0438\u044f \u0438 \u0431\u043b\u043e\u043a\u0438\u0440\u043e\u0432\u043a\u0430 \u043c\u0430\u0440\u0448\u0440\u0443\u0442\u043e\u0432 ID4me \u0443\u0440\u043e\u0432\u043d\u044f \u0432\u0435\u0431-\u043f\u0440\u0438\u043b\u043e\u0436\u0435\u043d\u0438\u0439 (WAF) \u0434\u043b\u044f \u0441\u0435\u0442\u0435\u0432\u043e\u0433\u043e \u0442\u0440\u0430\u0444\u0438\u043a\u0430;\n\n- \u0438\u0441\u043f\u043e\u043b\u044c\u0437\u043e\u0432\u0430\u043d\u0438\u0435 \u0441\u0440\u0435\u0434\u0441\u0442\u0432 \u0430\u043d\u0442\u0438\u0432\u0438\u0440\u0443\u0441\u043d\u043e\u0439 \u0437\u0430\u0449\u0438\u0442\u044b \u0434\u043b\u044f \u043f\u0440\u043e\u0432\u0435\u0440\u043a\u0438 \u0444\u0430\u0439\u043b\u043e\u0432, \u043f\u043e\u043b\u0443\u0447\u0435\u043d\u043d\u044b\u0445 \u0438\u0437 \u043d\u0435\u0434\u043e\u0432\u0435\u0440\u0435\u043d\u043d\u044b\u0445 \u0438\u0441\u0442\u043e\u0447\u043d\u0438\u043a\u043e\u0432;\n\n- \u043c\u0438\u043d\u0438\u043c\u0438\u0437\u0430\u0446\u0438\u044f \u043f\u043e\u043b\u044c\u0437\u043e\u0432\u0430\u0442\u0435\u043b\u044c\u0441\u043a\u0438\u0445 \u043f\u0440\u0438\u0432\u0438\u043b\u0435\u0433\u0438\u0439;\n- \u0438\u0441\u043f\u043e\u043b\u044c\u0437\u043e\u0432\u0430\u043d\u0438\u0435 \u0442\u043e\u043b\u044c\u043a\u043e \u0434\u043e\u0432\u0435\u0440\u0435\u043d\u043d\u044b\u0445 OIDC/ID4me-\u043f\u0440\u043e\u0432\u0430\u0439\u0434\u0435\u0440\u043e\u0432 \u0434\u043b\u044f \u0438\u0434\u0435\u043d\u0442\u0438\u0444\u0438\u043a\u0430\u0446\u0438\u0438;\n\n- \u0432\u043a\u043b\u044e\u0447\u0435\u043d\u0438\u0435 \u043c\u043d\u043e\u0433\u043e\u0444\u0430\u043a\u0442\u043e\u0440\u043d\u043e\u0439 \u0430\u0443\u0442\u0435\u043d\u0442\u0438\u0444\u0438\u043a\u0430\u0446\u0438\u0438 \u0434\u043b\u044f \u043f\u0440\u0438\u0432\u0438\u043b\u0435\u0433\u0438\u0440\u043e\u0432\u0430\u043d\u043d\u044b\u0445 \u0443\u0447\u0435\u0442\u043d\u044b\u0445 \u0437\u0430\u043f\u0438\u0441\u0435\u0439;\n\n- \u043e\u0442\u043a\u043b\u044e\u0447\u0435\u043d\u0438\u0435/\u0443\u0434\u0430\u043b\u0435\u043d\u0438\u0435 \u043d\u0435\u0438\u0441\u043f\u043e\u043b\u044c\u0437\u0443\u0435\u043c\u044b\u0445 \u0443\u0447\u0451\u0442\u043d\u044b\u0445 \u0437\u0430\u043f\u0438\u0441\u0435\u0439 \u043f\u043e\u043b\u044c\u0437\u043e\u0432\u0430\u0442\u0435\u043b\u0435\u0439;\n\n- \u043e\u0433\u0440\u0430\u043d\u0438\u0447\u0435\u043d\u0438\u0435 \u0434\u043e\u0441\u0442\u0443\u043f\u0430 \u0438\u0437 \u0432\u043d\u0435\u0448\u043d\u0438\u0445 \u0441\u0435\u0442\u0435\u0439 (\u0418\u043d\u0442\u0435\u0440\u043d\u0435\u0442).",
  "\u0414\u0430\u0442\u0430 \u0432\u044b\u044f\u0432\u043b\u0435\u043d\u0438\u044f": "07.01.2026",
  "\u0414\u0430\u0442\u0430 \u043f\u043e\u0441\u043b\u0435\u0434\u043d\u0435\u0433\u043e \u043e\u0431\u043d\u043e\u0432\u043b\u0435\u043d\u0438\u044f": "25.06.2026",
  "\u0414\u0430\u0442\u0430 \u043f\u0443\u0431\u043b\u0438\u043a\u0430\u0446\u0438\u0438": "25.06.2026",
  "\u0418\u0434\u0435\u043d\u0442\u0438\u0444\u0438\u043a\u0430\u0442\u043e\u0440": "BDU:2026-08694",
  "\u0418\u0434\u0435\u043d\u0442\u0438\u0444\u0438\u043a\u0430\u0442\u043e\u0440\u044b \u0434\u0440\u0443\u0433\u0438\u0445 \u0441\u0438\u0441\u0442\u0435\u043c \u043e\u043f\u0438\u0441\u0430\u043d\u0438\u0439 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "CVE-2026-45156, GHSA-qqgv-fqwp-mjpp",
  "\u0418\u043d\u0444\u043e\u0440\u043c\u0430\u0446\u0438\u044f \u043e\u0431 \u0443\u0441\u0442\u0440\u0430\u043d\u0435\u043d\u0438\u0438": "\u0423\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c \u0443\u0441\u0442\u0440\u0430\u043d\u0435\u043d\u0430",
  "\u041a\u043b\u0430\u0441\u0441 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u0423\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c \u0430\u0440\u0445\u0438\u0442\u0435\u043a\u0442\u0443\u0440\u044b",
  "\u041d\u0430\u0437\u0432\u0430\u043d\u0438\u0435 \u041f\u041e": "Nextcloud",
  "\u041d\u0430\u0438\u043c\u0435\u043d\u043e\u0432\u0430\u043d\u0438\u0435 \u041e\u0421 \u0438 \u0442\u0438\u043f \u0430\u043f\u043f\u0430\u0440\u0430\u0442\u043d\u043e\u0439 \u043f\u043b\u0430\u0442\u0444\u043e\u0440\u043c\u044b": null,
  "\u041d\u0430\u0438\u043c\u0435\u043d\u043e\u0432\u0430\u043d\u0438\u0435 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u0423\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c \u043c\u043e\u0434\u0443\u043b\u044f \u0430\u0432\u0442\u043e\u0440\u0438\u0437\u0430\u0446\u0438\u0438 User OIDC \u043e\u0431\u043b\u0430\u0447\u043d\u043e\u0433\u043e \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u043d\u043e\u0433\u043e \u043e\u0431\u0435\u0441\u043f\u0435\u0447\u0435\u043d\u0438\u044f \u0434\u043b\u044f \u0441\u043e\u0437\u0434\u0430\u043d\u0438\u044f \u0438 \u0438\u0441\u043f\u043e\u043b\u044c\u0437\u043e\u0432\u0430\u043d\u0438\u044f \u0445\u0440\u0430\u043d\u0438\u043b\u0438\u0449\u0430 \u0434\u0430\u043d\u043d\u044b\u0445 Nextcloud, \u043f\u043e\u0437\u0432\u043e\u043b\u044f\u044e\u0449\u0430\u044f \u043d\u0430\u0440\u0443\u0448\u0438\u0442\u0435\u043b\u044e \u043f\u043e\u0432\u044b\u0441\u0438\u0442\u044c \u0441\u0432\u043e\u0438 \u043f\u0440\u0438\u0432\u0438\u043b\u0435\u0433\u0438\u0438",
  "\u041d\u0430\u043b\u0438\u0447\u0438\u0435 \u044d\u043a\u0441\u043f\u043b\u043e\u0439\u0442\u0430": "\u0421\u0443\u0449\u0435\u0441\u0442\u0432\u0443\u0435\u0442 \u0432 \u043e\u0442\u043a\u0440\u044b\u0442\u043e\u043c \u0434\u043e\u0441\u0442\u0443\u043f\u0435",
  "\u041e\u043f\u0438\u0441\u0430\u043d\u0438\u0435 \u043e\u0448\u0438\u0431\u043a\u0438 CWE": "\u041d\u0435\u043f\u0440\u0430\u0432\u0438\u043b\u044c\u043d\u0430\u044f \u0430\u0443\u0442\u0435\u043d\u0442\u0438\u0444\u0438\u043a\u0430\u0446\u0438\u044f (CWE-287)",
  "\u041e\u043f\u0438\u0441\u0430\u043d\u0438\u0435 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u0423\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u044c \u043c\u043e\u0434\u0443\u043b\u044f \u0430\u0432\u0442\u043e\u0440\u0438\u0437\u0430\u0446\u0438\u0438 User OIDC \u043e\u0431\u043b\u0430\u0447\u043d\u043e\u0433\u043e \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u043d\u043e\u0433\u043e \u043e\u0431\u0435\u0441\u043f\u0435\u0447\u0435\u043d\u0438\u044f \u0434\u043b\u044f \u0441\u043e\u0437\u0434\u0430\u043d\u0438\u044f \u0438 \u0438\u0441\u043f\u043e\u043b\u044c\u0437\u043e\u0432\u0430\u043d\u0438\u044f \u0445\u0440\u0430\u043d\u0438\u043b\u0438\u0449\u0430 \u0434\u0430\u043d\u043d\u044b\u0445 Nextcloud \u0441\u0432\u044f\u0437\u0430\u043d\u0430 \u0441 \u043d\u0435\u0434\u043e\u0441\u0442\u0430\u0442\u043a\u0430\u043c\u0438 \u043f\u0440\u043e\u0446\u0435\u0434\u0443\u0440\u044b \u0430\u0443\u0442\u0435\u043d\u0442\u0438\u0444\u0438\u043a\u0430\u0446\u0438\u0438. \u042d\u043a\u0441\u043f\u043b\u0443\u0430\u0442\u0430\u0446\u0438\u044f \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438 \u043c\u043e\u0436\u0435\u0442 \u043f\u043e\u0437\u0432\u043e\u043b\u0438\u0442\u044c \u043d\u0430\u0440\u0443\u0448\u0438\u0442\u0435\u043b\u044e, \u0434\u0435\u0439\u0441\u0442\u0432\u0443\u044e\u0449\u0435\u043c\u0443 \u0443\u0434\u0430\u043b\u0435\u043d\u043d\u043e, \u043f\u043e\u0432\u044b\u0441\u0438\u0442\u044c \u0441\u0432\u043e\u0438 \u043f\u0440\u0438\u0432\u0438\u043b\u0435\u0433\u0438\u0438",
  "\u041f\u043e\u0441\u043b\u0435\u0434\u0441\u0442\u0432\u0438\u044f \u044d\u043a\u0441\u043f\u043b\u0443\u0430\u0442\u0430\u0446\u0438\u0438 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u041f\u043e\u0432\u044b\u0448\u0435\u043d\u0438\u0435 \u043f\u0440\u0438\u0432\u0438\u043b\u0435\u0433\u0438\u0439",
  "\u041f\u0440\u043e\u0447\u0430\u044f \u0438\u043d\u0444\u043e\u0440\u043c\u0430\u0446\u0438\u044f": null,
  "\u0421\u0432\u044f\u0437\u044c \u0441 \u0438\u043d\u0446\u0438\u0434\u0435\u043d\u0442\u0430\u043c\u0438 \u0418\u0411": "\u0414\u0430\u043d\u043d\u044b\u0435 \u0443\u0442\u043e\u0447\u043d\u044f\u044e\u0442\u0441\u044f",
  "\u0421\u043e\u0441\u0442\u043e\u044f\u043d\u0438\u0435 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u041e\u043f\u0443\u0431\u043b\u0438\u043a\u043e\u0432\u0430\u043d\u0430",
  "\u0421\u043f\u043e\u0441\u043e\u0431 \u0443\u0441\u0442\u0440\u0430\u043d\u0435\u043d\u0438\u044f": "\u041e\u0431\u043d\u043e\u0432\u043b\u0435\u043d\u0438\u0435 \u043f\u0440\u043e\u0433\u0440\u0430\u043c\u043c\u043d\u043e\u0433\u043e \u043e\u0431\u0435\u0441\u043f\u0435\u0447\u0435\u043d\u0438\u044f",
  "\u0421\u043f\u043e\u0441\u043e\u0431 \u044d\u043a\u0441\u043f\u043b\u0443\u0430\u0442\u0430\u0446\u0438\u0438": "\u041d\u0430\u0440\u0443\u0448\u0435\u043d\u0438\u0435 \u0430\u0443\u0442\u0435\u043d\u0442\u0438\u0444\u0438\u043a\u0430\u0446\u0438\u0438",
  "\u0421\u0441\u044b\u043b\u043a\u0438 \u043d\u0430 \u0438\u0441\u0442\u043e\u0447\u043d\u0438\u043a\u0438": "https://github.com/cybertechajju/CVE-2026-45156-POC\n\nhttps://github.com/nextcloud/security-advisories/security/advisories/GHSA-qqgv-fqwp-mjpp\n\nhttps://hackerone.com/reports/3489490",
  "\u0421\u0442\u0430\u0442\u0443\u0441 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u041f\u043e\u0434\u0442\u0432\u0435\u0440\u0436\u0434\u0435\u043d\u0430 \u043f\u0440\u043e\u0438\u0437\u0432\u043e\u0434\u0438\u0442\u0435\u043b\u0435\u043c",
  "\u0422\u0438\u043f \u041f\u041e": "\u041f\u0440\u0438\u043a\u043b\u0430\u0434\u043d\u043e\u0435 \u041f\u041e \u0438\u043d\u0444\u043e\u0440\u043c\u0430\u0446\u0438\u043e\u043d\u043d\u044b\u0445 \u0441\u0438\u0441\u0442\u0435\u043c",
  "\u0422\u0438\u043f \u043e\u0448\u0438\u0431\u043a\u0438 CWE": "CWE-287",
  "\u0423\u0440\u043e\u0432\u0435\u043d\u044c \u043e\u043f\u0430\u0441\u043d\u043e\u0441\u0442\u0438 \u0443\u044f\u0437\u0432\u0438\u043c\u043e\u0441\u0442\u0438": "\u0412\u044b\u0441\u043e\u043a\u0438\u0439 \u0443\u0440\u043e\u0432\u0435\u043d\u044c \u043e\u043f\u0430\u0441\u043d\u043e\u0441\u0442\u0438 (\u0431\u0430\u0437\u043e\u0432\u0430\u044f \u043e\u0446\u0435\u043d\u043a\u0430 CVSS 2.0 \u0441\u043e\u0441\u0442\u0430\u0432\u043b\u044f\u0435\u0442 9,4)\n\u0412\u044b\u0441\u043e\u043a\u0438\u0439 \u0443\u0440\u043e\u0432\u0435\u043d\u044c \u043e\u043f\u0430\u0441\u043d\u043e\u0441\u0442\u0438 (\u0431\u0430\u0437\u043e\u0432\u0430\u044f \u043e\u0446\u0435\u043d\u043a\u0430 CVSS 3.1 \u0441\u043e\u0441\u0442\u0430\u0432\u043b\u044f\u0435\u0442 8,1)"
}

CVE-2026-45156 (GCVE-0-2026-45156)

Vulnerability from cvelistv5 – Published: 2026-06-01 16:38 – Updated: 2026-06-03 03:55

Title

Nextcloud: Authentication Bypass in ID4me handling via Missing JWT Signature Verification in User OIDC

Summary

Nextcloud is an open source content collaboration platform. From versions 0.3.0 to before 3.1.0, 5.0.0 to before 5.1.0, and 6.0.0 to before 6.4.0, a missing signature verification in User OIDC allowed a malicious ID4me authority to identify as any user. This issue has been patched in versions 3.1.0, 4.1.0, 5.1.0, 6.4.0 and 8.3.0.

Severity

8.1 (High)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N

SSVC

Exploitation: none Automatable: no Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-06-02 00:00 UTC

CWE

CWE-287 - Improper Authentication

Assigner

GitHub_M mitre root

References

3 references

URL	Tags
https://github.com/nextcloud/security-advisories/…	x_refsource_CONFIRM
https://github.com/nextcloud/user_oidc/pull/1285	x_refsource_MISC
https://hackerone.com/reports/3489490	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
nextcloud	security-advisories	Affected: >= 0.3.0, < 3.1.0 Affected: >= 5.0.0, < 5.1.0 Affected: >= 6.0.0, < 6.4.0

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{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-45156",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-06-02T00:00:00+00:00",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-06-03T03:55:47.564Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "security-advisories",
          "vendor": "nextcloud",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 0.3.0, \u003c 3.1.0"
            },
            {
              "status": "affected",
              "version": "\u003e= 5.0.0, \u003c 5.1.0"
            },
            {
              "status": "affected",
              "version": "\u003e= 6.0.0, \u003c 6.4.0"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Nextcloud is an open source content collaboration platform. From versions 0.3.0 to before 3.1.0, 5.0.0 to before 5.1.0, and 6.0.0 to before 6.4.0, a missing signature verification in User OIDC allowed a malicious ID4me authority to identify as any user. This issue has been patched in versions 3.1.0, 4.1.0, 5.1.0, 6.4.0 and 8.3.0."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 8.1,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-287",
              "description": "CWE-287: Improper Authentication",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-06-01T16:38:46.470Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/nextcloud/security-advisories/security/advisories/GHSA-qqgv-fqwp-mjpp",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/nextcloud/security-advisories/security/advisories/GHSA-qqgv-fqwp-mjpp"
        },
        {
          "name": "https://github.com/nextcloud/user_oidc/pull/1285",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/nextcloud/user_oidc/pull/1285"
        },
        {
          "name": "https://hackerone.com/reports/3489490",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://hackerone.com/reports/3489490"
        }
      ],
      "source": {
        "advisory": "GHSA-qqgv-fqwp-mjpp",
        "discovery": "UNKNOWN"
      },
      "title": "Nextcloud: Authentication Bypass in ID4me handling via Missing JWT Signature Verification in User OIDC"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-45156",
    "datePublished": "2026-06-01T16:38:46.470Z",
    "dateReserved": "2026-05-08T20:44:38.964Z",
    "dateUpdated": "2026-06-03T03:55:47.564Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.