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Fencer Intel
high 8.7

CVE-2026-104979 json

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

published last mo. modified last mo. also EUVD-2026-92538

cvss
8.7
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 29%
public exploits
0
none known

Summary

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.

Patch / fix

  • plane plane 1.4.0

Is CVE-2026-104979 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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CISA SSVC

Exploitation
Proof of concept is public
Automatable
no
Technical impact
total
Assessed
last mo.

Exploit prediction

0.36% chance of exploitation in the next 30 days, higher than 29% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • github.com https://github.com/makeplane/plane/security/advisories/GHSA-hh2r-3hwp-mvq3 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 8.7 CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N

Affected products

  • makeplane plane

Classification

Weakness
  • CWE-79 Improper Neutralization of Input During Web Page Generation
  • CWE-862 Missing Authorization

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.