Bug bounty reports15,219
Publicly disclosed HackerOne reports, with the platform's own outcome and severity.
| Report | Status | Weakness | Severity | Disclosed | Bounty | Votes |
|---|---|---|---|---|---|---|
| Missing ownership check on remote wipe endpointAnalysed#819807 | Valid | Insecure Direct Object Reference | High | 2020-04-19 | $500 | 141 |
| Private circle can be added to another circle via API despite visibility restrictionAnalysed#3511998 | Valid | Insecure Direct Object Reference | Low | 2026-05-08 | $150 | 87 |
| WebAuthn app was updated based on public keyAnalysed#3360354 | Valid | Insecure Direct Object Reference | Low | 2026-02-06 | – | 84 |
| TaskProcessing callback authorization bypass allows ex-members to post as Assistant Talk BotAnalysed#3799010 | Valid | Insecure Direct Object Reference | Medium | 2026-08-14 | – | 73 |
| Files drop share links for end-to-end encrypted folders allowed to drop files into other folders of the share ownerAnalysed#3304830 | Valid | Insecure Direct Object Reference | Low | 2026-05-08 | – | 60 |
| Calendar app allowed booking appointments without the generated tokenAnalysed#3275810 | Valid | Insecure Direct Object Reference | Low | 2025-12-05 | – | 57 |
| Ability to read any emails through IDOR on Nextcloud MailAnalysed#1784681 | Valid | Insecure Direct Object Reference | Medium | 2023-04-12 | – | 34 |
| Share information of Tables app is not limited to affected usersAnalysed#2705507 | Valid | Insecure Direct Object Reference | Low | 2024-11-18 | – | 31 |
| Tables app allowed users to view columns metadata information of any table#3138721 | Valid | Insecure Direct Object Reference | Medium | 2025-12-05 | – | 30 |
| Missing ownership check in Tables app allows moving columns into tables of other usersAnalysed#3137895 | Valid | Insecure Direct Object Reference | Medium | 2025-12-05 | – | 30 |
| Enabling Birthday Contact to any userAnalysed#2112973 | Valid | Insecure Direct Object Reference | Medium | 2023-11-21 | – | 29 |
| IDOR unsubscribe Anyone from NextClouds Newsletters by knowing their EmailAnalysed#230328 | Valid | Insecure Direct Object Reference | Medium | 2017-09-16 | – | 29 |
| Participants were able to blindly delete poll drafts of other users by IDAnalysed#3247386 | Valid | Insecure Direct Object Reference | Medium | 2025-12-05 | – | 27 |
| Possibility to delete files attached to deck cards of other usersAnalysed#1755555 | Valid | Insecure Direct Object Reference | Low | 2023-01-09 | – | 21 |
| Access control missing while viewing the attachments in the "All boards"Analysed#916704 | Valid | Insecure Direct Object Reference | Medium | 2020-09-29 | $150 | 20 |
| Team membership information returned on API level based on IDAnalysed#3484601 | Valid | Insecure Direct Object Reference | Low | 2026-09-17 | $200 | 19 |
| Registered users can change app password permissions for any userAnalysed#297751 | Valid | Insecure Direct Object Reference | Low | 2018-02-08 | $100 | 18 |
| Nextcloud Deck : Possibility for anyone to add a stack with existing tasks on anyone's boardAnalysed#1450117 | Valid | Insecure Direct Object Reference | Medium | 2022-05-20 | – | 13 |
| Ownership check missing when updating or deleting attachments#1579820 | Valid | Insecure Direct Object Reference | Medium | 2022-07-06 | – | 7 |
| New users can read all Nextcloud Deck data from previous user with same username#882258 | Valid | Insecure Direct Object Reference | Low | 2021-02-14 | – | 3 |
Status and severity are HackerOne's. “Access stated” is what the title says; “Access needed” and techniques come from CyberSIXT's analysis of the public report, where there is one, which can be wrong. Data as of 2026-11-15.