CVE-2026-118678
n8n before 2.41.4 and 2.42.1 Prototype Pollution DoS via Workflow History Compaction
n8n before 2.41.4 and 2.42.x before 2.42.1 contains a prototype pollution vulnerability that allows low-privileged users to alter built-in object behaviour by saving workflows with specially named connection keys. Attackers can add keys such as proto to workflow connections, which the periodic history compaction task processes, causing logins and writes to fail with server errors.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- Low
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
n8n before 2.41.4 and 2.42.1 Prototype Pollution DoS via Workflow History Compaction
n8n before 2.41.4 and 2.42.x before 2.42.1 contains a prototype pollution vulnerability that allows low-privileged users to alter built-in object behaviour by saving workflows with specially named connection keys. Attackers can add keys such as proto to workflow connections, which the periodic history compaction task processes, causing logins and writes to fail with server errors.
- Record
CVE-2026-118678- CVSS 4.0
- 7.1 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N - CVSS 3.1
- 7.1 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H - Weakness
- CWE-1321
- Updated
- 2026-11-02
EUVDEUVD-2026-112384
n8n before 2.41.4 and 2.42.x before 2.42.1 contains a prototype pollution vulnerability that allows low-privileged users to alter built-in object behaviour by saving workflows with specially named connection keys. Attackers can add keys such as proto to workflow connections, which the periodic history compaction task processes, causing logins and writes to fail with server errors.
- Record
EUVD-2026-112384- CVSS 4.0
- 7.1 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-4v4v-jr32-r382
n8n before 2.41.4 and 2.42.x before 2.42.1 contains a prototype pollution vulnerability that...
n8n before 2.41.4 and 2.42.x before 2.42.1 contains a prototype pollution vulnerability that allows low-privileged users to alter built-in object behaviour by saving workflows with specially named connection keys. Attackers can add keys such as proto to workflow connections, which the periodic history compaction task processes, causing logins and writes to fail with server errors.
- Record
GHSA-4v4v-jr32-r382- CVSS 4.0
- 7.1 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 7.1 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H - Weakness
- CWE-1321
- Updated
- 2026-11-02
NVD
n8n before 2.41.4 and 2.42.x before 2.42.1 contains a prototype pollution vulnerability that allows low-privileged users to alter built-in object behaviour by saving workflows with specially named connection keys. Attackers can add keys such as proto to workflow connections, which the periodic history compaction task processes, causing logins and writes to fail with server errors.
- Record
CVE-2026-118678- CVSS 4.0
- 7.1 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 7.1 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:H - Weakness
- CWE-1321
- Updated
- 2026-11-02
OSV
n8n before 2.41.4 and 2.42.1 Prototype Pollution DoS via Workflow History Compaction
n8n before 2.41.4 and 2.42.x before 2.42.1 contains a prototype pollution vulnerability that allows low-privileged users to alter built-in object behaviour by saving workflows with specially named connection keys. Attackers can add keys such as proto to workflow connections, which the periodic history compaction task processes, causing logins and writes to fail with server errors.
- Record
CVE-2026-118678- CVSS 4.0
- 7.1 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N - Weakness
- CWE-1321
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-118678 is a high vulnerability (CVSS 7.1) in N8n-io N8n, published October 28, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.29%, the 22nd percentile. No source names a fixed version.
References
github.com/n8n-io/n8n/security/advisories/GHSA-fvv4-gmv9-xqf5
vulncheck.com/advisories/n8n-before-2.41.4-and-2.42.1-prototype-pollution-dos-via-workflow-history-compaction
nvd.nist.gov/vuln/detail/CVE-2026-118678