CVE-2023-53977

Name: CVE-2023-53977
Creator: NVD / NIST
Published: 2025-12-22T22:16:03.203+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.1/10EPSS 0.19%

Last modified Jun 17, 2026

CVE-2023-53977 is a medium-severity vulnerability rated 5.1/10 on the CVSS scale. myBB Forums 1.8.26 contains a stored cross-site scripting vulnerability in the forum management system that allows authenticated administrators to inject malicious scripts when creating new forums. Attackers can exploit this vulnerability by inserting script payloads in the forum title field when adding new forums through the 'Forums and Posts' > 'Forum Management' interface, causing arbitrary JavaScript to execute when the forum listing is viewed.. EPSS estimates a 0.19% chance of exploitation in the next 30 days.

Description

myBB Forums 1.8.26 contains a stored cross-site scripting vulnerability in the forum management system that allows authenticated administrators to inject malicious scripts when creating new forums. Attackers can exploit this vulnerability by inserting script payloads in the forum title field when adding new forums through the 'Forums and Posts' > 'Forum Management' interface, causing arbitrary JavaScript to execute when the forum listing is viewed.

Metrics

CVSS 3.1

5.4/10

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

CVSS 4.0

5.1/10

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS Probability

0.19%

9.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-79

Affected Software

Vendor	Product	Versions
Mybb	Mybb	1.8.26

References

https://mybb.com/Product
https://www.exploit-db.com/exploits/51136Exploit
https://www.vulncheck.com/advisories/mybb-forums-stored-cross-site-scripting-via-forum-managementExploit, Third Party Advisory

Timeline

Published: Dec 22, 2025
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2023-53977?

How severe is CVE-2023-53977?

CVE-2023-53977 has a CVSS score of 5.1/10 (MEDIUM severity). The EPSS model estimates a 0.19% probability of exploitation in the next 30 days.

How do I fix CVE-2023-53977?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2023-53977?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST