CVE-2026-21858

CRITICALNVD 10.010.0—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 10.0 under NVD CVSS v3. EPSS exploit probability: 71.6%, top 1% 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, nvd
Trending — 3 sources updated this weekElevated
10.0EG
EchelonGraph verdictPatch this weekExploitation is likely or a public exploit exists.
  • High exploitation likelihood — EPSS 72%
CISA-KEV: Not listedEPSS PROB: 72%CVSS: 10.0Exploit: Elevated riskExposed: 0

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

n8n is an open source workflow automation platform. Versions starting with 1.65.0 and below 1.121.0 enable an attacker to access files on the underlying server through execution of certain form-based workflows. A vulnerable workflow could grant access to an unauthenticated remote attacker, resulting in exposure of sensitive information stored on the system and may enable further compromise depending on deployment configuration and workflow usage. This issue is fixed in version 1.121.0.

CVSS v3
10.0
EG Score
10.0(medium)
EG Risk
89(Track)
EG Risk 89/100SSVC: 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
Severity100% × 45%
Exploitation72% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
72%
EPSS %ILE
99%
KEV
Not listed

Published

January 8, 2026

Last Modified

January 16, 2026

Advisory Details (2)

Auto-updated Jul 25, 2026
Patch available. Sources: github.
generic

Ni8mare - Unauthenticated Remote Code Execution in n8n (CVE-2026-21858)

https://www.cyera.com/research-labs/ni8mare-unauthenticated-remote-code-execution-in-n8n-cve-2026-21858
github Patch Available

Unauthenticated File Access via Improper Webhook Request Handling · Advisory · n8n-io/n8n · GitHub

https://github.com/n8n-io/n8n/security/advisories/GHSA-v4pr-fm98-w9pg

Affected Packages

(1 across 1 ecosystem)
npm(1)
PackageVulnerable rangeFixed inDependents
n8n—1.121.0—

Weakness Classification(1)

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

Data Freshness Timeline

(refreshed 7× in last 7d / 19× 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. 2026-07-25 14:17 UTCEPSS rescore
  2. 2026-07-25 14:17 UTCEPSS rescore
  3. 2026-07-24 14:17 UTCEPSS rescore
  4. 2026-07-23 11:19 UTCOSV refresh
  5. 2026-07-23 03:06 UTCEG score recompute
  6. 2026-07-22 14:08 UTCEPSS rescore
  7. 2026-07-20 17:08 UTCEPSS rescore
  8. 2026-07-19 02:29 UTCEPSS rescore
  9. 2026-07-19 02:28 UTCEPSS rescore
  10. 2026-07-15 16:57 UTCEPSS rescore
  11. 2026-07-15 16:57 UTCEPSS rescore
  12. 2026-07-13 06:13 UTCEPSS rescore
  13. 2026-07-13 06:13 UTCEPSS rescore
  14. 2026-07-11 08:27 UTCEPSS rescore
  15. 2026-07-09 19:10 UTCEPSS rescore
  16. 2026-07-07 13:46 UTCEPSS rescore
  17. 2026-07-06 06:02 UTCOSV refresh
  18. 2026-07-04 06:31 UTCEPSS rescore
  19. 2026-07-04 06:31 UTCEPSS rescore
  20. 2026-06-27 03:08 UTCEPSS rescore
  21. 2026-06-25 13:49 UTCEPSS rescore
  22. 2026-06-24 14:05 UTCEPSS rescore
  23. 2026-06-23 21:32 UTCEPSS rescore
  24. 2026-06-21 14:56 UTCEPSS rescore
  25. 2026-06-21 14:56 UTCEPSS rescore
Show 35 more
  1. 2026-06-21 01:59 UTCEPSS rescore
  2. 2026-06-21 01:59 UTCEPSS rescore
  3. 2026-06-18 17:52 UTCEPSS rescore
  4. 2026-06-17 17:53 UTCEPSS rescore
  5. 2026-06-17 17:44 UTCOSV refresh
  6. 2026-06-16 17:52 UTCEPSS rescore
  7. 2026-06-15 17:48 UTCEPSS rescore
  8. 2026-06-14 23:18 UTCEPSS rescore
  9. 2026-06-13 23:00 UTCEPSS rescore
  10. 2026-06-13 23:00 UTCEPSS rescore
  11. 2026-06-12 23:12 UTCEPSS rescore
  12. 2026-06-11 14:00 UTCEPSS rescore
  13. 2026-06-10 22:18 UTCEPSS rescore
  14. 2026-06-10 13:22 UTCEPSS rescore
  15. 2026-06-08 14:17 UTCEPSS rescore
  16. 2026-06-08 14:17 UTCEPSS rescore
  17. 2026-06-07 15:25 UTCEPSS rescore
  18. 2026-06-07 15:24 UTCEPSS rescore
  19. 2026-06-05 22:47 UTCEPSS rescore
  20. 2026-06-04 13:12 UTCEPSS rescore
  21. 2026-06-04 13:12 UTCEPSS rescore
  22. 2026-06-04 13:12 UTCEPSS rescore
  23. 2026-06-02 20:13 UTCEPSS rescore
  24. 2026-06-02 20:13 UTCEPSS rescore
  25. 2026-06-01 13:51 UTCEPSS rescore
  26. 2026-06-01 13:51 UTCEPSS rescore
  27. 2026-06-01 13:51 UTCEPSS rescore
  28. 2026-05-31 22:30 UTCEPSS rescore
  29. 2026-05-31 22:30 UTCEPSS rescore
  30. 2026-05-31 00:16 UTCEPSS rescore
  31. 2026-05-31 00:16 UTCEPSS rescore
  32. 2026-05-31 00:16 UTCEPSS rescore
  33. 2026-05-29 16:30 UTCEG score recompute
  34. 2026-05-29 13:44 UTCEPSS rescore
  35. 2026-05-29 13:44 UTCEPSS rescore

Publicly available exploits

(3 references)

Working exploit code is in the public domain (2 GitHub PoCs). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • GitHub PoCSystemVll/CVE-2026-21858
    First seen Jan 20, 2026

    Proof of Concept: CVE-2026-21858 is vulnerability on n8n where unauthenticated remote attackers can access sensitive files.

    Open source ↗
  • GitHub PoCsh4den/CVE-2026-21858
    First seen Jan 20, 2026

    Proof of Concept: CVE-2026-21858 is vulnerability on n8n where unauthenticated remote attackers can access sensitive files.

    Open source ↗
  • Nucleihttp/cves/2026/CVE-2026-21858.yaml
    First seen Jan 1, 2026

    n8n Webhooks - Remote Code Execution

    Open source ↗

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-21858?
CVE-2026-21858 is a critical vulnerability published on January 8, 2026. n8n is an open source workflow automation platform. Versions starting with 1.65.0 and below 1.121.0 enable an attacker to access files on the underlying server through execution of certain form-based workflows. A vulnerable workflow could grant access to an unauthenticated remote attacker,…
When was CVE-2026-21858 disclosed?
CVE-2026-21858 was first published in the National Vulnerability Database on January 8, 2026, with the most recent update on January 16, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-21858 actively exploited?
CVE-2026-21858 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 72% probability of exploitation in the next 30 days, which ranks it in the top 0.6% of all scored CVEs.
What is the CVSS score of CVE-2026-21858?
CVE-2026-21858 has a CVSS v3 base score of 10.0 (NVD).
How do I remediate CVE-2026-21858?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-21858, 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

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-21858

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