Description

Uncontrolled Resource Consumption vulnerability in oban-bg oban_web ('Elixir.Oban.Web.CronExpr' modules) allows memory exhaustion via unbounded cron range expansion. An attacker with access to schedule cron jobs can submit a malicious cron expression such as "0 0 1-100000000 * *". When a user with dashboard access views the cron job list, 'Elixir.Oban.Web.CronExpr':describe/1 is called to render the expression. parse_range/1 parses both range endpoints via Integer.parse/1 with no bounds check, and the downstream helpers expand_dom_parts/1 and expand_dow_parts/1 materialise the range eagerly via Enum.to_list/1, causing allocation of ~2.4 GB and stalling or crashing the BEAM node. A sibling helper extract_dom_values already validates range bounds, but the expansion helpers do not. This issue affects oban_web: from 2.12.0 before 2.12.5.

Weaknesses 1

References 4

• cna.erlef.org https://cna.erlef.org/cves/CVE-2026-48593.html
• github.com https://github.com/oban-bg/oban_web/commit/9998b7e284e02fdd4645dd6231760038e63b584d
• github.com https://github.com/oban-bg/oban_web/security/advisories/GHSA-6xh2-93p9-vqh4
• osv.dev https://osv.dev/vulnerability/EEF-CVE-2026-48593

Remediation