vikunja before 2.6.0 Team Enumeration via Project Share

CISA KEV is observed exploitation evidence. FIRST EPSS is a dated prediction of exploitation in the next 30 days. Missing scores are unknown. This collector requests predictions only for explicit CVE aliases in the public NuGet archive; Microsoft release views retain their existing prediction scope.

No collected risk observation for these identifiers. This does not establish absence of exploitation or a zero probability.

vikunja before 2.6.0 fails to validate team access when attaching teams to projects, allowing authenticated users to enumerate all teams and members. Attackers can attach arbitrary team IDs via the project teams endpoint to retrieve complete team rosters including member names and admin flags for unauthorized teams.

Source published

15 Sep 2026 15:18:24 UTC

Source modified

15 Sep 2026 16:03:30 UTC

Observed here

23 Oct 2026 15:48:27 UTC

Source terms

CVE Program Terms of Use

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CVSS 3.1 · 4.3 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

CVSS 4.0 · 5.3 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

vikunja before 2.6.0 fails to validate team access when attaching teams to projects, allowing authenticated users to enumerate all teams and members. Attackers can attach arbitrary team IDs via the project teams endpoint to retrieve complete team rosters including member names and admin flags for unauthorized teams.

Source published

Sep 15, 2026, 3:18:24 PM (timezone not stated)

Source modified

Sep 15, 2026, 4:03:30 PM (timezone not stated)

Observed here

7 Nov 2026 15:25:03 UTC

Source terms

ENISA EUVD · source terms and attribution apply

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EUVD CVSS 4.0 · 5.3 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

vikunja before 2.6.0 fails to validate team access when attaching teams to projects, allowing authenticated users to enumerate all teams and members. Attackers can attach arbitrary team IDs via the project teams endpoint to retrieve complete team rosters including member names and admin flags for unauthorized teams.

Source published

15 Sep 2026 16:17:54 UTC

Source modified

16 Sep 2026 19:49:18 UTC

Observed here

25 Oct 2026 16:19:22 UTC

Source terms

NIST NVD usage terms; underlying source attribution retained

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: nvd · NIST NVD usage terms; underlying source attribution retained. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS 4.0 · [email protected] · Secondary · 5.3 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

CVSS 3.1 · [email protected] · Secondary · 4.3 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

### Duplicate Advisory This advisory has been withdrawn because it is a duplicate of GHSA-39p5-2wrr-xh29. This link is maintained to preserve external references. ### Original Description vikunja before 2.6.0 fails to validate team access when attaching teams to projects, allowing authenticated users to enumerate all teams and members. Attackers can attach arbitrary team IDs via the project teams endpoint to retrieve complete team rosters including member names and admin flags for unauthorized teams.

Source published

15 Sep 2026 18:32:30 UTC

Source modified

9 Oct 2026 21:00:05 UTC

Observed here

24 Oct 2026 13:19:41 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V3 · CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

CVSS_V4 · 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Publisher rating · MODERATE

### Summary When you share a project with a team, the API lets you attach any team on the instance, including teams you have nothing to do with, as long as you're an admin of the project. Listing a project's teams then returns each team's full member roster. So any logged-in user can spin up a throwaway project, attach team IDs one by one, and read back the name, description, and complete member list of every team on the instance. Normally you can only see teams you belong to; this path ignores that. ### Details Sharing a project with a team is a two-step flow: you PUT a team to the project, then you GET the project's teams to see them. The share endpoint only enforces that you're an admin of the target project, it doesn't care whether the team you're referencing is one you're allowed to see. Any existing team ID is accepted. The listing endpoint is even more permissive: read access to the project is enough, which you obviously have on a project you created. And its response isn't just a list of team names, it includes each team's description, creator, and a full members array with every member's username, display name, and admin flag. Put together, an attacker who owns a single project can walk the team ID space and pull the roster of every team in the instance, including teams they aren't a member of. This contradicts how team visibility works everywhere else in the product, where you only ever see teams you belong to. Emails are stripped from the roster, so what leaks is identities and org structure rather than contact details. The fix is to require that the caller actually has access to the team they're attaching, not just to the project. ### PoC The attacker needs nothing but an ordinary account. 1. Create a throwaway project you own: 2. Attach team IDs one by one (sweep the range you want): ``` PUT /api/v1/projects/<your_project_id>/teams {<SNIP>, "team_id": <N>, <SNIP>} ``` 3. Read them back with their rosters: ``` GET /api/v1/projects/<your_project_id>/teams ``` Each entry contains the team name, description, creator, and a members array with every member's username, display name, and admin flag, for teams you are not a member of. ### Impact Information disclosure of the instance-wide team directory: team names, descriptions, and full membership, for teams the attacker has no relationship with. This maps out the organisation's group structure and who belongs where, useful for targeting and social engineering. Any authenticated account is enough; no share link, no admin rights, no victim interaction.

Source published

9 Oct 2026 20:52:27 UTC

Source modified

19 Oct 2026 21:41:05 UTC

Observed here

24 Oct 2026 13:19:41 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V4 · 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

Publisher rating · MODERATE

Vikunja: Any user can enumerate every team and its members by attaching arbitrary teams to a throwaway project in code.vikunja.io/api. NOTE: The source advisory for this report contains additional versions that could not be automatically mapped to standard Go module versions. (If this is causing false-positive reports from vulnerability scanners, please suggest an edit to the report.) The additional affected modules and versions are: code.vikunja.io/api before v2.6.0.

Source published

19 Oct 2026 21:08:26 UTC

Source modified

19 Oct 2026 21:31:36 UTC

Observed here

24 Oct 2026 13:19:41 UTC

Source terms

OSV · upstream source license applies

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · OSV · upstream source license applies. Source text is retained; field grouping and change labels are provided by ChangeIntel.