CVE-2026-21858

Q: How do I fix CVE-2026-21858?

Upgrade n8n to 1.121.0 or later.

Q: Is CVE-2026-21858 being actively exploited?

Not that we know of. CVE-2026-21858 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 78.2% is the estimated probability that it will be exploited in the next 30 days. That is higher than 100% of all scored CVEs.

Q: How severe is CVE-2026-21858?

CVE-2026-21858 has a CVSS v3 base score of 10.0, rated critical. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.

Q: What does CVE-2026-21858 affect?

Published advisories record a fix for n8n (NVD). Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.

CRITICALEPSS 100th pctl

10.0

CVSS v3

NVD

Description

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.

CWE-20Improper Input Validation

How to fix

Remediation Available

n8nNVD

Affected:>= 1.65.0, < 1.121.0Fixed in:1.121.0CVE-2026-21858derived from NVD

TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

ScopeChanged

Impact

ConfidentialityHigh

IntegrityHigh

AvailabilityNone

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N

Exploit Intelligence

78.20%probability of exploitation in 30 days

100thpercentile

Very high risk: more likely to be exploited than 100% of all known CVEs.

References

Exploit1

cyera.com

Vendor Advisory1

github.com

Related Vulnerabilities

Other CWE-20 (Improper Input Validation) vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2024-3400	Critical	10.0	100%	KEV + Ransom	-
CVE-2021-45105	Medium	5.9	100%	-	Fix
CVE-2021-44228	Critical	10.0	100%	KEV + Ransom	Fix
CVE-2021-21985	Critical	9.8	100%	KEV + Ransom	Fix
CVE-2020-3452	High	7.5	100%	KEV	Fix
CVE-2018-7600	Critical	9.8	100%	KEV + Ransom	Fix

Common questions

How do I fix CVE-2026-21858?

Upgrade n8n to 1.121.0 or later.

Is CVE-2026-21858 being actively exploited?

Not that we know of. CVE-2026-21858 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 78.2% is the estimated probability that it will be exploited in the next 30 days. That is higher than 100% of all scored CVEs.

How severe is CVE-2026-21858?

CVE-2026-21858 has a CVSS v3 base score of 10.0, rated critical. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.

What does CVE-2026-21858 affect?

Published advisories record a fix for n8n (NVD). Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-01-16.