Vikunja: Every /api/v2 pre-auth endpoint is unthrottled on a stock install while its /api/v1 twin is rate limited

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

8.7 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N · score source

EPSS

• CVE-2026-91972: 0.63% estimated exploitation activity in the next 30 days; percentile 50.41 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary registerAPIRoutesV2 never applies the unconditional pre-auth rate-limit floor (unauthRateLimit()) to the v2 public routes — it passes that limiter only to /api/v2/ws — and otherwise relies on setupRateLimit, which registers nothing when ratelimit.enabled is false (the default). So on a stock install every v2 pre-auth endpoint (login, register, password-reset token, oauth token) is unthrottled, while its v1 twin is throttled. Details unauthRateLimit() - perMinuteIPRateLimit("noauth", RateLimitNoAuthRoutesLimit) (pkg/routes/ratelimit.go, ~lines 100-118) is an unconditional per-IP floor (default 10/60s) that deliberately ignores RateLimitEnabled, which is why v1's pre-auth routes are throttled even with the global limiter off. v1 applies it: ur := a.Group(""); ur.Use(unauthRateLimit()) (pkg/routes/routes.go ~line 459). registerAPIRoutesV2 (~lines 405-431) passes the unauthRateLimit() instance only to /api/v2/ws; its auth routes get only setupRateLimit(a, ...), which is…

Published by the source

9 Oct 2026, 20:51 UTC

Last modified by the source

19 Oct 2026, 21:31 UTC

Source last checked

26 Oct 2026, 15:32 UTC

1. Revision 4 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-6rvj-qwjf-3m4q

2. Revision 3 · amended · 25 Oct 2026

   Reviewed OSV alias/range/CVSS4 correction; package source scopes and original publication preserved. No customer finding resolved.

3. Revision 2 · amended · 24 Oct 2026

   Amended from osv record GO-2026-6721

4. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-6rvj-qwjf-3m4q

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# Patch Next advisory brief: CVE-2026-91972

Advisory: Vikunja: Every /api/v2 pre-auth endpoint is unthrottled on a stock install while its /api/v1 twin is rate limited
IDs: CVE-2026-91972, GHSA-6rvj-qwjf-3m4q
Record: https://patchnext.com/advisories/cve-2026-91972 (revision 4, source checked 26 Oct 2026, 15:32 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.7)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: code.vikunja.io/api 2.6.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go code.vikunja.io/api: affected <= 2.5.0; fixed in 2.6.0

## Suggested inspection (read-only)
- Go code.vikunja.io/api: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on code.vikunja.io/api.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GO-2026-6721 (OSV record GO-2026-6721 lists affected ranges: Go code.vikunja.io/api >=0)
- Verified: https://osv.dev/vulnerability/GHSA-6rvj-qwjf-3m4q (OSV record GHSA-6rvj-qwjf-3m4q lists affected ranges: Go code.vikunja.io/api >=0 <2.6.0 (fixed))
- Verified: https://github.com/advisories/GHSA-6rvj-qwjf-3m4q (GitHub-reviewed advisory GHSA-6rvj-qwjf-3m4q lists affected ranges: Go code.vikunja.io/api >=0 <=2.5.0)

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