Discourse is an option source discussion platform. Prior to version 2.8.14 on the stable branch and version 2.9.0.beta16 on the beta and tests-passed branches, parsing posts can be susceptible to regular expression denial of service (ReDoS) attacks. This issue is patched in versions 2.8.14 and 2.9.0.beta16. There are no known workarounds.
Weakness
The product uses a regular expression with a worst-case computational complexity that is inefficient and possibly exponential.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Discourse | Discourse | * | 2.8.14 (excluding) |
| Discourse | Discourse | 2.9.0-beta1 (including) | 2.9.0-beta1 (including) |
| Discourse | Discourse | 2.9.0-beta10 (including) | 2.9.0-beta10 (including) |
| Discourse | Discourse | 2.9.0-beta11 (including) | 2.9.0-beta11 (including) |
| Discourse | Discourse | 2.9.0-beta12 (including) | 2.9.0-beta12 (including) |
| Discourse | Discourse | 2.9.0-beta13 (including) | 2.9.0-beta13 (including) |
| Discourse | Discourse | 2.9.0-beta14 (including) | 2.9.0-beta14 (including) |
| Discourse | Discourse | 2.9.0-beta2 (including) | 2.9.0-beta2 (including) |
| Discourse | Discourse | 2.9.0-beta3 (including) | 2.9.0-beta3 (including) |
| Discourse | Discourse | 2.9.0-beta4 (including) | 2.9.0-beta4 (including) |
| Discourse | Discourse | 2.9.0-beta5 (including) | 2.9.0-beta5 (including) |
| Discourse | Discourse | 2.9.0-beta6 (including) | 2.9.0-beta6 (including) |
| Discourse | Discourse | 2.9.0-beta7 (including) | 2.9.0-beta7 (including) |
| Discourse | Discourse | 2.9.0-beta8 (including) | 2.9.0-beta8 (including) |
| Discourse | Discourse | 3.0.0-beta15 (including) | 3.0.0-beta15 (including) |