CVE-2026-49249 Boruta: Authenticated atom-exhaustion DoS in BorutaIdentityWeb.UserSettingsController.update/2
Authenticated users can crash the Boruta OIDC server by exhausting the BEAM atom table via unvalidated keys in user settings updates.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-49249?
CVE-2026-49249 is a high-severity denial of service vulnerability in malach-it boruta-server, published on 2 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Boruta is a standalone authorization server that aims to implement OAuth 2.0 and Openid Connect up to decentralized identity specifications. Prior to version 0.10.0, BorutaIdentityWeb.UserSettingsController.update/2 atomizes every key of the user-supplied request body via String.to_atom/1 before any validation. Because String.to_atom interns atoms permanently in the BEAM atom table (default cap 1,048,576 atoms; ERL_MAX_ATOMS), any authenticated end user can send PUT /users/settings with a user[<fresh-key>]=... body containing fresh keys per request and exhaust the global VM atom table. Once the table is full, the BEAM aborts with no more index entries in atom_tab and the entire OIDC server (auth, admin, gateway apps in the umbrella) crashes. The route is protected only by require_authenticated_user and a per-IP rate limit of 10 requests/second; a logged-in end user can hit it. The keys are atomized unconditionally before the downstream Accounts.update_user/6 call, so even failing updates contribute to exhaustion. This issue has been patched in version 0.10.0.
Which versions are affected by CVE-2026-49249?
How do I fix CVE-2026-49249?
No fix has been published for CVE-2026-49249 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-49249 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-49249 exists.
Sources
Also known as GHSA-q428-ch8m-94gg.