Resource exhaustion in Discourse
CVE-2025-68934
Discourse is an open source discussion platform. In versions prior to 3.5.4, 2025.11.2, 2025.12.1, and 2026.1.0, authenticated users can submit crafted payloads to /drafts.json that cause O(n^2) processing in Base62.decode, tying up workers for 35-60 seconds per request. This affects all users as the shared worker pool becomes exhausted. This issue is patched in versions 3.5.4, 2025.11.2, 2025.12.1, and 2026.1.0. Lowering the max_draft_length site setting reduces attack surface but does not fully mitigate the issue, as payloads under the limit can still trigger the slow code path.
EPSS: 0.002 (14.5th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.
Affected products
- Discourse — versions >= 2026.1.0-latest, < 2026.1.0, >= 2025.12.0-latest, 2025.12.1, < 3.5.4
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Third Party Advisory, Mitigation)
Frequently asked questions
- What is CVE-2025-68934?
- CVE-2025-68934 is a medium-severity vulnerability in Discourse, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 6.5/10. Published 2026-01-28.
- How severe is CVE-2025-68934?
- Medium severity. CVSS v3 base score is 6.5 out of 10.