Discourse Anonymous Cache Poisoning via Header Manipulation
CVE-2025-23023 Published on February 4, 2025
Anonymous cache poisoning via request headers in Discourse
Discourse is an open source platform for community discussion. In affected versions an attacker can carefully craft a request with the right request headers to poison the anonymous cache (for example, the cache may have a response with missing preloaded data). This issue only affects anonymous visitors of the site. This problem has been patched in the latest version of Discourse. Users are advised to upgrade. Users unable to upgrade may disable anonymous cache by setting the `DISCOURSE_DISABLE_ANON_CACHE` environment variable to a non-empty value.
Vulnerability Analysis
CVE-2025-23023 can be exploited with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality, a high impact on integrity, and a small impact on availability.
Weakness Type
Origin Validation Error
The software does not properly verify that the source of data or communication is valid.
Products Associated with CVE-2025-23023
Want to know whenever a new CVE is published for Discourse? stack.watch will email you.
Affected Versions
discourse:- Version stable: < 3.3.2 is affected.
- Version tests-passed: < 3.4.0.beta3 is affected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.