High severity · published Oct 5, 2026
CVE-2026-104979
Plane: Cross-tenant stored XSS in intake enables account takeover
8.7
CVSS
0.4%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
Required
Confidentiality
High
Integrity
High
Availability
None
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 29% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
PL
plane · makeplane
< 1.4.0 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-104979
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-104979
x_refsource_CONFIRM
https://github.com/makeplane/plane/security/advisories/GHSA-hh2r-3hwp-mvq3
x_refsource_MISC
https://github.com/makeplane/plane/pull/9287
x_refsource_MISC
https://github.com/makeplane/plane/commit/0d58adb69d859fc94c43b9d68fadd77e810d5ed1
x_refsource_MISC
https://github.com/makeplane/plane/releases/tag/v1.4.0
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