What’s Vulnerable › Vulnerabilities

CVE-2026-104979: Plane: Cross-tenant stored XSS in intake enables account takeover

• Severity: high (CVSS 8.7 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-10-05 · updated 2026-10-05
• Weakness: CWE-79

Description

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.

Affected products

• makeplane plane: before 1.4.0

References

• https://github.com/makeplane/plane/commit/0d58adb69d859fc94c43b9d68fadd77e810d5ed1
• https://github.com/makeplane/plane/pull/9287
• https://github.com/makeplane/plane/releases/tag/v1.4.0
• https://github.com/makeplane/plane/security/advisories/GHSA-hh2r-3hwp-mvq3
• https://github.com/makeplane/plane/security/advisories/GHSA-hh2r-3hwp-mvq3

Get alerted when CVE-2026-104979 or the next vulnerability affects your stack