Discourse is an open source platform for community discussion. This vulnerability only impacts Discourse instances configured to use `FileStore::LocalStore` which means uploads and backups are stored locally on disk. If an attacker knows the name of the Discourse backup file, the attacker can trick nginx into sending the Discourse backup file with a well crafted request. This issue is patched in the latest stable, beta and tests-passed versions of Discourse. Users are advised to upgrade. Users unable to upgrade can either 1. Download all local backups on to another storage device, disable the `enable_backups` site setting and delete all backups until the site has been upgraded to pull in the fix. Or 2. Change the `backup_location` site setting to `s3` so that backups are stored and downloaded directly from S3.
Conclusion & alert: CVE-2024-53991 is rated Moderate Risk (59.2/100): CVSS High severity, with high exploitation likelihood (EPSS 25.43%, 98th percentile). Core evidence: EPSS ranks this CVE among the most likely to be exploited in the near term. Mandatory action: High exploitation likelihood—assess exposure and prioritize remediation.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-06-15 | 53.12% | 25.43% | -27.69% |
| 2 | 2026-05-10 | 46.64% | 53.12% | +6.48% |
| 3 | 2026-05-09 | — | 46.64% | — |
Full EPSS history (43 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 7.5 | 3.1 | HIGH |
|
3.9 | 3.6 | [email protected] |
| 5.9 | 3.1 | MEDIUM |
|
2.2 | 3.6 | [email protected] |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| discourse | discourse | < 3.3.2 | cpe:2.3:a:discourse:discourse:*:*:*:*:stable:*:*:* |
| discourse | discourse | < 3.4.0 | cpe:2.3:a:discourse:discourse:*:*:*:*:beta:*:*:* |
| discourse | discourse | 3.4.0 | cpe:2.3:a:discourse:discourse:3.4.0:beta1:*:*:beta:*:*:* |
| discourse | discourse | 3.4.0 | cpe:2.3:a:discourse:discourse:3.4.0:beta2:*:*:beta:*:*:* |
| discourse | discourse | 3.4.0 | cpe:2.3:a:discourse:discourse:3.4.0:beta3:*:*:beta:*:*:* |
| URL | Tags |
|---|---|
| https://github.com/discourse/discourse/security/advisories/GHSA-567m-82f6-56rv | Mitigation Third Party Advisory |