Skip to content

Nextcloud · disclosed report #3040887

Users can modify tags on files that do not belong to them

No analysis yet · $150 bounty · 20 votes

No analysis of this report yet. What HackerOne publishes about it is below, with the link to the report.

Read the researcher's report

Read the researcher's report on HackerOne

No analysis of this report yet. What HackerOne publishes about it is below, with the link to the report. Ask for a correction or removal.

Similar findings, side by side
ReportAccessWhose objectBoundary crossed
Account Takeover via Password Reset without user interactionsNo accountAnother user'sThe password-reset flow sent another user's reset link to an attacker-controlled address.
Exfiltrate and mutate repository and project data through injected templated serviceA user accountAnother tenant'sA regular user imported administrator-only templates that were then installed in projects created by other users.
Getting all the CD keys of any gameA user accountAnother user'sA partner user retrieved another game's CD keys despite lacking access to that game.
Ability to reset password for accountNo accountAnother user'sThe password-reset feature sent reset links to addresses selected by the requester.
Publicly accessible Continuous Integration ToolNo accountNo object involvedA public user accessed an internal CI instance and its sensitive data.
One-click account hijack for anyone using Apple sign-in with Reddit, due to response-type switch + leaking href to XSS on www.redditmedia.comNo accountAnother user'sA victim’s OAuth credentials were exposed to an attacker-controlled page through cross-window access.
Reset password link sent over unsecured http protocolNo accountThe attacker's ownA network observer could obtain the reset token from the account owner's HTTP request.
Full account takeoverNo accountAnother user'sThe login flow allegedly accepts a token issued to another application to authenticate as a different user.
Attacker is able to access commit title and team member comments which are supposed to be privateA user accountAnother user'sA non-team member received email notifications containing activity from a team-only project.
Private list members disclosure via GraphQLA user accountAnother user'sA caller accessed another user's private-list membership through GraphQL after discovering its identifier.
Exposed proxy allows to access internal reddit domainsNo accountNo object involvedAn unauthenticated external request was reportedly proxied to an internal domain.
[CRITICAL] 0-Click Account Takeover via Password Reset [AUTH-3243] /orchestrator/v1/password_reset/startA user accountAnother user'sAn attacker’s password-reset flow was reportedly able to change another user’s account password using that user’s reset data.
Program
Nextcloud
Status
Valid
Severity
Medium
Bounty
$150
Weakness as filed
Improper Access Control - Generic
Disclosed
2026
Upvotes
20

Data as of 2026-11-14. CVE List through 2026-11-14 · EPSS of 2026-11-14 · CISA KEV checked 2026-11-14. Sources: the CVE List, CISA KEV, EPSS, NVD, nuclei templates and public bug bounty data. Use this via MCP

Updated AboutDevelopersSign in