CVE-2026-105639

CRITICALPre-NVD 9.89.8
EchelonGraph scoreLOW confidence

This critical-severity CVE scores 9.8 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: secondary
9.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: —CVSS: 9.8Exploit: None knownExposed services: Not assessed

A fix is available — apply it.

Plane is an open-source project management tool. Prior to 1.4.0, Plane's signup flow creates a logged-in User row for any submitted email without an out-of-band ownership check, while User.email is unique=True. The authenticated user can call GET /api/users/me/workspaces/invitations/, which returns each WorkspaceMemberInvite whose email matches request.user.email. WorkSpaceMemberInviteSerializer uses fields = "all", exposing the token that protects the invitation join endpoint. An unauthenticated attacker who knows a target's email can register an account using that address, enumerate pending invitations, and accept an invitation as the target, joining a workspace at the invited role. The term pre-auth describes the attacker's initial state: the attacker has no credential before signup, while the enumeration and join requests use the session created by that signup. This issue is fixed in 1.4.0.

CVSS v3
9.8
EG Score
9.8CRITICALlow confidence
EG Risk
49
EG Risk 49/100CISA SSVC

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity98% × 45%
Exploitation0% × 40%
Automatability30% × 15%
CISA SSVC: Track at low or medium mission impact; Track* or Attend at high (mission-essential systems).
Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
EPSS PROB
—
EPSS %ILE
—
KEV
Not listed

CISA SSVCTrack at low or medium mission impact; Track* or Attend at high (mission-essential systems).

A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.

Exploitation none (no KEV listing, exploit record or EPSS ≥ 50%) · Automatable unknown (not published for this CVE) · Technical impact total (CVSS ≥ 9.0). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table

Published

October 5, 2026

Last Modified

October 5, 2026

Advisory Details (4)

Auto-updated Oct 5, 2026
🔬 Proof of concept available. Patch available. Sources: github_commit, github_pr, github_release, github.
githubMentions a patch (unverified)🟡 PoC Available

Pre-auth workspace invitation hijack via email-squat and self-served invitation token leak in Plane · Advisory · makeplane/plane · GitHub

https://github.com/makeplane/plane/security/advisories/GHSA-4vj8-p63v-8p24
github_release Patch Available

v1.4.0

Patch available: makeplane/plane v1.4.0

https://github.com/makeplane/plane/releases/tag/v1.4.0
github_pr

[WEB-7854] fix: prevent workspace invite token disclosure and invite hijack

Fix merged in makeplane/plane PR #9297 on 2026-06-23 — awaiting tagged release

https://github.com/makeplane/plane/pull/9297
github_commit

commit 6220ba990b22 (makeplane/plane)

Fix landed in makeplane/plane commit 6220ba990b22 — awaiting tagged release

https://github.com/makeplane/plane/commit/6220ba990b2276a1a1979d1d5df68f650b8b47ad

Weakness Classification(3)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 3× in last 7d / 3× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-10-05 19:24 UTCEG score recompute
  2. 2026-10-05 18:26 UTCEG score recompute
  3. 2026-10-05 18:25 UTCMITRE cvelistV5first tracked

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Frequently asked(4)

What is CVE-2026-105639?
CVE-2026-105639 is a critical vulnerability published on October 5, 2026. Plane is an open-source project management tool. Prior to 1.4.0, Plane's signup flow creates a logged-in User row for any submitted email without an out-of-band ownership check, while User.email is unique=True. The authenticated user can call GET /api/users/me/workspaces/invitations/, which returns…
When was CVE-2026-105639 disclosed?
CVE-2026-105639 was first published on October 5, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
What is the CVSS score of CVE-2026-105639?
CVE-2026-105639 has a CVSS base score of 9.8 (a secondary CVSS source that NVD displays; NVD's own analysis pending). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-105639?
A fix for CVE-2026-105639 is available: update to the fixed version the vendor names in its advisory.

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