CVE-2026-21858
High PUBLISHEDn8n Vulnerable to Unauthenticated File Access via Improper Webhook Request Handling
Not yet in CISA KEV
Recommended Action
Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.
At a Glance
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.
- CVE Published
- Jan 07, 2026
- Exploitation Reported
- Feb 07, 2026
- CVSS
- 10.0 Critical
- EPSS
- —
Affected Versions
| Vendor | Product | Version | Status |
|---|---|---|---|
| n8n-io |
n8n
|
>= 1.65.0, < 1.121.0 |
Affected |
CVE References
- https://github.com/n8n-io/n8n/security/advisories/GHSA-v4pr-fm98-w9pg github.com · CVE Record https://github.com/n8n-io/n8n/security/advisories/GHSA-v4pr-fm98-w9pg
- https://www.cyera.com/research-labs/ni8mare-unauthenticated-remote-code-execution-in-n8n-cve-2026-21858 cyera.com · CVE Record https://www.cyera.com/research-labs/ni8mare-unauthenticated-remote-co...
Recommended Actions
- Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.
- Check enrichment artifacts for scanner coverage and available PoCs before rolling remediation validation.
- Use the Pro API to automate enrichment, telemetry, and workflow delivery for VM, SOC, and CTI pipelines.
Known Exploited Vulnerability Sources
Catalogues that list this CVE as a known exploited vulnerability.
Per-source evidence links for KEV attestations are available through the KEVIntel Pro API.
Learn about Pro API access| Source | Added |
|---|---|
| The Shadowserver First | 2026-02-07 00:00 UTC |
Scanner Artifacts
Nuclei and Metasploit references linked to this CVE.
| Scanner | Reference | Detected |
|---|---|---|
| Nuclei | https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2026/CVE-2026-21858.yaml | Jun 01, 2026 |
Virtual Patch
Compensating WAF rules to help reduce exposure to this CVE. Rule content and deployable vendor exports are available with KEVIntel Enterprise.
KEVIntel does not currently have a virtual patch for this CVE. When available, KEVIntel virtual patches ship as deployable ModSecurity, Cloudflare, and AWS WAF rules.
Enterprise feature. Virtual patch rule content and deployable vendor exports (ModSecurity, Cloudflare, AWS WAF) are available to KEVIntel Enterprise users.
CVSS Scores
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N
Exploitation Status
Exploited in the wild
Recorded 2026-02-07 00:00:00 UTC · The Shadowserver
Proof of concept available
Recorded 2026-01-07 19:32:42 UTC · GitHub
Weaknesses (CWE)
-
Improper Input Validation
Scanner Integrations
| Scanner | Reference | Detected |
|---|---|---|
| Nuclei | https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2026/CVE-2026-21858.yaml | Jun 01, 2026 |
Potential Proof of Concepts
These PoCs are unverified and could contain malware. Use at your own risk.
github · Created 2026-02-24 05:04:15 UTC · 0 stars
github · Created 2026-01-20 15:59:48 UTC · 3 stars
Proof of Concept: CVE-2026-21858 is vulnerability on n8n where unauthenticated remote attackers can access sensitive files.
github · Created 2026-01-20 15:59:48 UTC · 3 stars
Proof of Concept: CVE-2026-21858 is vulnerability on n8n where unauthenticated remote attackers can access sensitive files.
github · Created 2026-01-20 11:50:32 UTC · 1 stars
github · Created 2026-01-17 04:57:53 UTC · 0 stars
SASTRA-ADI-WIGUNA-CVE-2026-21858-Holistic-Audit
github · Created 2026-01-07 19:32:42 UTC · 257 stars
n8n Ni8mare - Unauthenticated Arbitrary File Read to RCE Chain (CVSS 10.0)
nuclei · Created Unknown
Timeline
Key exploitation, disclosure, scanner coverage, and KEV attestation events for this CVE.
-
15:34 UTC about 2 months ago15:34 UTC · about 2 months ago
Nuclei template available
Scanner coverage available
-
00:00 UTC 5 months ago00:00 UTC · 5 months ago
Added to KEVIntel KEV Feed
High-confidence, third-party attested exploitation
-
23:57 UTC 6 months ago23:57 UTC · 6 months ago
CVE published
Vulnerability disclosed publicly
-
19:32 UTC 6 months ago19:32 UTC · 6 months ago
Public PoC available
Public proof-of-concept code published
-
16:44 UTC 7 months ago16:44 UTC · 7 months ago
CVE ID reserved
Identifier reserved by the CNA
Automate This Intelligence with the Pro API
Confidence scoring, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.
Pro API Example
GET /api/v2/pro/kevs/CVE-2026-21858
{
"cve_id": "CVE-2026-21858",
"title": "n8n Vulnerable to Unauthenticated File Access via Improper Webhook Request Ha...",
"affected_vendor": "n8n-io",
"affected_product": "n8n",
"affected_versions": [
{ "vendor": "...", "product": "...", "status": "affected", "display_label": "..." }
],
"confidence": "High",
"cvss_score": 10.0,
"epss_score": null,
"exploit_status": {
"exploited_in_the_wild": true,
"active_exploitation_observed": false
},
"sensor_telemetry": { "...": "Pro API fields" },
"proof_of_concepts": [ "..." ],
"scanner_integrations": [ "..." ]
}