CVE-2026-55210

HIGHPre-NVD 7.47.4—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.4 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.5%, top 61% of all CVEs by exploit prediction. 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: epss, secondary
Trending — 3 sources updated this week
7.4EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 7.4Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

Joplin is an open source note-taking and to-do application that organises notes and lists into notebooks. Prior to 3.7.2, Joplin Server's UserModel.ssoLogin() returns an existing account matched by an IdP-asserted email without checking the account's is_external flag. In deployments using mixed local and SAML authentication, an attacker whose IdP session can assert a local user's email can pass POST /api/saml, receive a session for that local account, and access or modify the victim's notes, files, and settings without knowing the local password. This issue is fixed in version 3.7.2.

CVSS v3
7.4
EG Score
7.4(medium)
EG Risk
33(Track)
EG Risk 33/100SSVC: Track

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
Severity74% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
39%
KEV
Not listed

Published

September 21, 2026

Last Modified

September 23, 2026

Advisory Details (3)

Auto-updated Sep 21, 2026
Patch available. Sources: github_pr, github_commit, github.
github_commit

commit b6d69d072919 (laurent22/joplin)

Fix landed in laurent22/joplin commit b6d69d072919 — awaiting tagged release

https://github.com/laurent22/joplin/commit/b6d69d072919cbe769234f93d95ed21e1ec129b2
github_pr

Server: Prevent SAML login from accessing existing local password accounts

Fix merged in laurent22/joplin PR #15647 on 2026-06-11 — awaiting tagged release

https://github.com/laurent22/joplin/pull/15647
github Patch Available

SAML SSO account takeover via email-based account linking (missing is_external check in ssoLogin) · Advisory · laurent22/joplin · GitHub

https://github.com/laurent22/joplin/security/advisories/GHSA-5px3-4f5x-hjc5

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 10× in last 7d / 10× 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. 2026-09-24 20:00 UTCEG score recompute
  2. 2026-09-24 14:04 UTCEPSS rescore
  3. 2026-09-23 18:39 UTCEG score recompute
  4. 2026-09-23 17:54 UTCEPSS rescore
  5. 2026-09-23 03:00 UTCEG score recompute
  6. 2026-09-22 14:20 UTCEG score recompute
  7. 2026-09-22 13:27 UTCEG score recompute
  8. 2026-09-21 22:27 UTCEG score recompute
  9. 2026-09-21 21:27 UTCEG score recompute
  10. 2026-09-21 21:26 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-55210?
CVE-2026-55210 is a high vulnerability published on September 21, 2026. Joplin is an open source note-taking and to-do application that organises notes and lists into notebooks. Prior to 3.7.2, Joplin Server's UserModel.ssoLogin() returns an existing account matched by an IdP-asserted email without checking the account's is_external flag. In deployments using mixed…
When was CVE-2026-55210 disclosed?
CVE-2026-55210 was first published in the National Vulnerability Database on September 21, 2026, with the most recent update on September 23, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-55210 actively exploited?
CVE-2026-55210 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 61.3% of all scored CVEs.
What is the CVSS score of CVE-2026-55210?
CVE-2026-55210 has a CVSS v3 base score of 7.4 (NVD).
How do I remediate CVE-2026-55210?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-55210, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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