CVE-2026-58417

Description

### Summary The endpoint "/orgs/{org}/public_members/{username}" + GET exposes organization membership of public members in a private organization. ### PoC 1. Spin up the nightly container of Gitea. 2. Perform the default installation. 3. Register a new user (let's call this user "user1"). 4. Create a new organization with "private" visibility. We will refer to this organization as "user1org". 5. Make the user "user1" inside the organization visible. 6. Log out and register a new user ("user2"). 7. Create an access token for "user2" with full access to the API. 8. Use the endpoint "/orgs/{org}/public_members/{username}" + GET with the correct username of "user1", organization name, and access token of "user2" to query whether "user1" is a member of the organization. The following curl command demonstrates the usage: curl -X 'GET' \ 'http://localhost:4700/api/v1/orgs/user1org/public_members/user1' \ -H 'accept: application/json' \ -H 'authorization: token <user2-token>' 9. You will receive status code 204, which leaks the organization membership. ### Impact The vulnerability discloses organization membership. An information that is not accessible via the web app (the organization is hidden, and therefore, the organization membership on the user's profile page is also hidden).

How to fix CVE-2026-58417

To remediate CVE-2026-58417, upgrade the affected package to a fixed version below.

—upgrade to 1.27.0 or later

Is CVE-2026-58417 being exploited?

No exploitation signal available. Neither CISA KEV nor a current EPSS score has been published for CVE-2026-58417.

Affected packages (1)

from 0, < 1.27.0

CVSS scores

Source	Version	Severity	Vector
osv	CVSS 4.0	—	CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N