CVE-2026-49249: Boruta: Authenticated atom-exhaustion DoS in BorutaIdentityWeb.UserSettingsController.update/2

Severity: high (CVSS 7.1 v4.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-09-02 · updated 2026-09-09
Weakness: CWE-400

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.

Affected products

malach-it boruta-server: before 0.10.0

References

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