CVE-20XX-?
agent?

CVE-2026-45123

4.3 MEDIUM 0.4% exploit odds Fix listed Disclosure Web app

What it is

MyBB is free and open source forum software. Prior to 1.8.40, the remote requests feature does not correctly handle IPv6 addresses, resulting in a server-side request forgery vulnerability. The default disallowed remote hosts list does not include IPv6 addresses. Verification in fetch_remote_file() fails open when get_ip_by_hostname() returns no result because that function does not return IPv6 results, allowing a crafted remote target to bypass the host restriction. The uniquely identifying implementation details include fail-open verification, and inc/functions.php. This issue is fixed in version 1.8.40.

At a glance

Exploitability
Can be exploited over the network with a low-privilege account. Limited direct impact.
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. PublishedDisclosed publicly on CVE.org and NVD
  2. Last updatedMost recent change to the record

Why it ranks here

Details

Published
Last modified
Exploit probability
0.4% · EPSS, next 30 days
Weakness
CWE-918 · Server-side request forgery
Record status
Deferred

Attack profile CVSS 3.1 · 4.3

Attack vector
Network
Complexity
Low
Privileges needed
Low
User interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
None
Raw vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

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-2026-45123.md and follow it. Check whether this project is affected by CVE-2026-45123. 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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Fix and advisories

References

NVD record · CVE.org record