#VU103651 Origin validation error in Discourse - CVE-2025-23023

Vulnerability identifier: #VU103651

Vulnerability risk: High

CVSSv4.0: 6.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N/E:U/U:Amber]

CVE-ID: CVE-2025-23023

CWE-ID: CWE-346

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Discourse
Web applications / Forum & blogging software

Vendor: Civilized Discourse Construction Kit, Inc.

Description

The vulnerability allows a remote attacker to compromise the target system.

The vulnerability exists due to the cache poisoning issue within request headers. A remote attacker can use a specially crafted request with the right request headers to poison the anonymous cache.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Discourse: 3.3.0 beta1 - 3.4.0 beta2

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External links
https://github.com/discourse/discourse/security/advisories/GHSA-5h4h-2f46-r3c7

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.