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PatchSiren cyber security CVE debrief

CVE-2018-25247 MyBB CVE debrief

The MyBB Like Plugin 3.0.0 contains a stored cross-site scripting vulnerability. Authenticated attackers can inject script payloads into post or thread subjects; when other users view a profile that displays the attacker's liked posts, the unsanitized subject is rendered, executing the script in the viewer's browser. This vulnerability has a CVSS score of 5.1 and is rated as MEDIUM. The vulnerability is caused by the lack of input validation and output encoding for user-supplied data. The affected product is MyBB with the Like Plugin 3.0.0 installed.

Vendor
MyBB
Product
MyBB Like Plugin
CVSS
MEDIUM 5.1
CISA KEV
Not listed in stored evidence
Original CVE published
2026-04-04
Original CVE updated
2026-07-21
Advisory published
2026-04-04
Advisory updated
2026-07-21

Who should care

Users of MyBB with the Like Plugin 3.0.0 installed should be aware of this vulnerability and take steps to mitigate it. This includes updating the plugin to a version that fixes the vulnerability, implementing input validation and output encoding for user-supplied data, and monitoring user profiles and liked posts for suspicious activity. Security teams and vulnerability management teams should also be aware of this vulnerability and review the affected product deployments in their managed environments.

Technical summary

The MyBB Like Plugin 3.0.0 is vulnerable to stored cross-site scripting. An authenticated attacker can inject a script payload into post or thread subjects. When another user views a profile displaying the attacker's liked posts, the unsanitized subject is rendered, executing the script in the viewer's browser. The vulnerability is rated as MEDIUM with a CVSS score of 5.1. The vulnerability is caused by the lack of input validation and output encoding for user-supplied data.

Defensive priority

Medium priority due to the potential for user interaction-based attacks.

Recommended defensive actions

  • Update the MyBB Like Plugin to a version that fixes the stored cross-site scripting vulnerability.
  • Implement input validation and output encoding for user-supplied data.
  • Monitor user profiles and liked posts for suspicious activity.
  • Consider implementing a web application firewall to detect and prevent cross-site scripting attacks.
  • Review compensating controls for exposed systems while remediation is scheduled and verified.
  • Check relevant monitoring, detection, and logs for exposed assets that need extra review.
  • Track exceptions, retest remediated assets, and close the item only after evidence is documented.

Evidence notes

The CVE record was published on 2026-04-04T14:16:20.500Z and was last modified on 2026-07-21T07:10:00.117Z. The NVD entry is currently Modified. This information is based on the NVD entry and the CVE record. The vulnerability affects MyBB with the Like Plugin 3.0.0 installed. Evidence of exploitation is not currently available, but defenders should verify the affected product deployments in their managed environments.

Official resources

AI-assisted PatchSiren debrief based on the supplied source corpus. The CVE record was published on 2026-04-04T14:16:20.500Z and has not been modified since then.