CVE-2025-68934

MEDIUM

Discourse <3.5.4,2025.11.2,2025.12.1,2026.1.0 - Use After Free

Title source: llm
STIX 2.1

Description

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.

References (1)

Core 1
Core References
Third Party Advisory, Mitigation x_refsource_confirm
https://github.com/discourse/discourse/security/advisories/GHSA-vwjh-vrx9-9849

Scores

CVSS v3 6.5
EPSS 0.0024
EPSS Percentile 14.1%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact partial

Details

CWE
CWE-770
Status published
Products (3)
discourse/discourse 2025.12.0
discourse/discourse 2026.1.0
discourse/discourse < 3.5.4
Published Jan 28, 2026
Tracked Since Feb 18, 2026