CVE-2023-22488

What it is

Flarum is a forum software for building communities. Using the notifications feature, one can read restricted/private content and bypass access checks that would be in place for such content. The notification-sending component does not check that the subject of the notification can be seen by the receiver, and proceeds to send notifications through their different channels. The alerts do not leak data despite this as they are listed based on a visibility check, however, emails are still sent out. This means that, for extensions which restrict access to posts, any actor can bypass the restriction by subscribing to the discussion if the Subscriptions extension is enabled. The attack allows the leaking of some posts in the forum database, including posts awaiting approval, posts in tags the user has no access to if they could subscribe to a discussion before it becomes private, and posts restricted by third-party extensions. All Flarum versions prior to v1.6.3 are affected. The vulnerability has been fixed and published as flarum/core v1.6.3. All communities running Flarum should upgrade as soon as possible to v1.6.3. As a workaround, disable the Flarum Subscriptions extension or disable email notifications altogether. There are no other supported workarounds for this issue for Flarum versions below 1.6.3.

At a glance

Exploitability

Can be exploited over the network with a low-privilege account, but needs a user to act. High risk of data exposure.

Exploit odds

0.4% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2023-01-12 20:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 05:35 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.4% in the next 30 days (EPSS).
• Severity: 6.8 MEDIUM (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2023-01-12 20:15 UTC

Last modified

2026-06-17 05:35 UTC

Exploit probability

0.4% · EPSS, next 30 days

Weakness

CWE-862 · Missing authorization

Record status

Modified

Affected

• Flarum < 1.6.3

Attack profile CVSS 3.1 · 6.8

Attack vector

Network

Complexity

Low

Privileges needed

Low

User interaction

Required

Scope

Changed

Confidentiality

High

Integrity

None

Availability

None

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2023-22488.md and follow it. Check whether this project is affected by CVE-2023-22488. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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