# CVE-2026-104979: Plane cross-site scripting in intake item descriptions

Source: https://junglewise.ai/threats/cve-2026-104979-plane-is-an-open-source-project-management-tool-prior-to-1-4-0  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-05. Updated: 2026-10-05  
License: CC BY 4.0 with a link back

CVE-2026-104979 · Severity: high · CVSS 8.7 · Published 2026-10-05

Plane is an open-source project management tool that allows teams to create and track work items. Prior to version 1.4.0, attackers could inject malicious HTML into published intake items without restrictions. When project members view a crafted intake item, the malicious code executes in their browser session and steals their API authentication tokens, allowing account takeover.

Technologies: [Plane](https://junglewise.ai/threats/technologies/plane-plane). Vendors: [Plane](https://junglewise.ai/threats/vendors/plane).

## Quick answers

**Is CVE-2026-104979 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-104979 being exploited in the wild.

**How severe is CVE-2026-104979?** High severity, with a CVSS score of 8.7, published 5 October 2026.

**Which products and versions are affected?** Plane before 1.4.0.

**Is there a fix for CVE-2026-104979?** Yes: fixed in 1.4.0. Until then: Upgrade to Plane 1.4.0 or later, which sanitizes intake description_html and comment_html using the nh3 library. Disable the intake feature on published DeployBoards until patching can be completed. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-104979 attacked?** It is attacked over the network, in a web application.

**Am I affected by CVE-2026-104979?** Check whether you run Plane at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in 1.4.0

Upgrade to Plane 1.4.0 or later, which sanitizes intake description_html and comment_html using the nh3 library. Disable the intake feature on published DeployBoards until patching can be completed.

## Technical details

The IntakeIssuePublicViewSet.create endpoint in Plane v1.3.1 writes user-supplied description_html directly to the database via Issue.objects.create() without calling the validate_html_content() sanitization function. An authenticated user (even with no workspace membership) can inject arbitrary HTML that bypasses TipTap's javascript: parser via a target="_self" click handler. When project members or intake viewers click the malicious link, JavaScript executes in their session context and exfiltrates long-lived API tokens.

## Affected products

- Plane Plane before 1.4.0

## Timeline

- 2026-10-05: disclosed
- 2026-06-23: patched

## References

- [https://github.com/makeplane/plane/commit/0d58adb69d859fc94c43b9d68fadd77e810d5ed1](https://github.com/makeplane/plane/commit/0d58adb69d859fc94c43b9d68fadd77e810d5ed1)
- [https://github.com/makeplane/plane/pull/9287](https://github.com/makeplane/plane/pull/9287)

## Related threats

- [Plane project management missing authorization checks](https://junglewise.ai/threats/cve-2026-102985-plane-is-an-open-source-project-management-tool-in-1-3-1-and)
- [Plane order_by injection in issue-listing endpoints](https://junglewise.ai/threats/cve-2026-102988-plane-is-an-open-source-project-management-tool-prior-to-1-4-0)
- [Plane stored XSS in comments and intake descriptions](https://junglewise.ai/threats/cve-2026-102982-plane-is-an-open-source-project-management-tool-prior-to-1-4-0)
- [Plane workspace invitation token disclosure and hijack](https://junglewise.ai/threats/cve-2026-102981-plane-is-an-open-source-project-management-tool-prior-to-1-4-0)
- [Plane hardcoded Django SECRET_KEY in community deployments](https://junglewise.ai/threats/cve-2026-105641-plane-is-an-open-source-project-management-tool-prior-to-1-4-0)