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TI-2026-67848 Aliases CVE-2026-104979

Cross-tenant stored XSS in Plane intake enables account takeover

Priority HIGH 73CWE-79Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
Required
Attack complexity
Low
Impact type
Cross-site scripting, Security bypass
Confidentiality · integrity · availability
High · High · None
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-79 and CWE-862.

Summary

Plane versions before 1.4.0 store HTML submitted through intake without sanitization, a cross-site scripting flaw (CWE-79). Any authenticated user, including a new user with no workspace memberships, can plant HTML in a project with a published DeployBoard and intake enabled. When a project member or viewer clicks a planted link on a closed intake item, the injected JavaScript runs in their session and can steal a long-lived API token.

Written with Claude Haiku 5.5 from the sources below · 2026-10-29

Description from the CNA

Plane is an open-source project management tool. Prior to 1.4.0, IntakeIssuePublicViewSet.create in Plane v1.3.1 writes description_html through Issue.objects.create(...) without calling validate_html_content from nh3. Any authenticated user, including a new user with no workspace memberships, can plant arbitrary HTML in a project that has a published DeployBoard with intake enabled. When a project member or viewer of a closed intake item clicks the planted link, the TipTap \tjavascript: parser bypass and the target="_self" click handler execute JavaScript in the viewer's session and exfiltrate a long-lived API token. This issue is fixed in 1.4.0.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00359 29th percentileScored 2026-11-07
Fix Fixed plane (makeplane): 1.4.0

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
makeplaneplanebefore 1.4.01.4.0Patch availableCNA
  • plane Vendormakeplane Affected before 1.4.0 Fixed in 1.4.0 Patch available CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:a:plane:plane:*:*:*:*:*:*:*:*——makeplane
  • cpe:2.3:a:plane:plane:*:*:*:*:*:*:*:* Versions — — ·makeplane

Remediation

Upgrade Plane to version 1.4.0 or later, which fixes this issue.

Written with Claude Haiku 5.5 from the sources below · 2026-10-29

  • Fix · CNA plane (makeplane) Fixed in 1.4.0

Timeline

  1. 2026-10-05 Threatist record created from CVE-2026-104979
  2. 2026-10-05 CISA SSVC decision points changed
  3. 2026-10-05 Priority changed: MEDIUM → HIGH

References

Other 4

  • TI-2026-67866 Hardcoded secret keys in Plane community deployments CVSS 3.1CRITICAL 9.8
  • TI-2026-67865 Account takeover in Plane via unverified OAuth email matching CVSS 3.1CRITICAL 9.1
  • TI-2026-67863 Plane magic-code login lacks rate limiting, allowing OTP brute force CVSS 3.1CRITICAL 9.1
  • TI-2024-32097 Plane allows server side request forgery via /_next/image endpoint CVSS 3.1CRITICAL 9.3
  • TI-2026-67862 Cross-project asset hijacking in Plane allows file takeover CVSS 3.1CRITICAL 9.6
  • TI-2026-67861 Server-side request forgery in Plane webhook delivery via redirects CVSS 3.1CRITICAL 9.9
See all 65 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences