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GHSA-5vf7-q87h-pg6w

MediumCVSS 6.3 / 10
Published May 7, 2020·Last modified Mar 13, 2026
Affected Components(0)

No affected components available

Description

Impact

A user with permission to create comments could POST HTML directly to the system to be saved in a comment, which would then be executed/displayed to others users viewing the comment. Through this vulnerability custom JavaScript code could be injected and therefore ran on other user machines.

This most impacts scenarios where not-trusted users are given permission to create comments.

Patches

The issue was addressed in BookStack v0.29.2.

After upgrading, The command php artisan bookstack:regenerate-comment-content should be ran to remove any pre-existing dangerous content.

Workarounds

Comments can be disabled in the system settings to prevent them being shown to users. Alternatively, comment creation permissions can be altered as required to only those who are trusted but this will not address existing exploitation of this vulnerability.

References

For more information

If you have any questions or comments about this advisory:

Risk Scores
Base Score
6.3

The vulnerability can be exploited over the network without needing physical access. It is easy for an attacker to exploit this vulnerability. An attacker needs basic access or low-level privileges. No user interaction is needed for the attacker to exploit this vulnerability. The impact is confined to the system where the vulnerability exists. There is a low impact on the confidentiality of the information. There is a low impact on the integrity of the data. There is a low impact on the availability of the system.

Threat Intelligence
5.8

Exploitation attempts have been detected. Elevated vigilance and prompt remediation are advised.

EPSS
0.78%

The exploit probability is very low. The vulnerability is unlikely to be exploited in the next 30 days.

Exploit
Not available

We did not find any exploit available. Neither in GitHub repositories nor in the Exploit-Database.

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