CVE-2025-48053: Discourse vulnerable to DoS via large URL payload in PM to a bot
Description
Discourse is an open-source discussion platform. Prior to version 3.4.4 of the `stable` branch, version 3.5.0.beta5 of the `beta` branch, and version 3.5.0.beta6-dev of the `tests-passed` branch, sending a malicious URL in a PM to a bot user can cause a reduced the availability of a Discourse instance. This issue is patched in version 3.4.4 of the `stable` branch, version 3.5.0.beta5 of the `beta` branch, and version 3.5.0.beta6-dev of the `tests-passed` branch. No known workarounds are available.
Classification
CVE ID: CVE-2025-48053
CVSS Base Severity: HIGH
CVSS Base Score: 8.7
CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Problem Types
CWE-400: Uncontrolled Resource Consumption CWE-770: Allocation of Resources Without Limits or ThrottlingAffected Products
Vendor: discourse
Product: discourse
Exploit Prediction Scoring System (EPSS)
EPSS Score: 0.06% (probability of being exploited)
EPSS Percentile: 17.38% (scored less or equal to compared to others)
EPSS Date: 2025-06-24 (when was this score calculated)
References
https://nvd.nist.gov/vuln/detail/CVE-2025-48053https://github.com/discourse/discourse/security/advisories/GHSA-3q5q-qmrm-rvwx