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Fencer Intel
medium 4.3

CVE-2026-77082 json

n8n before 1.123.69 ReDoS via Filter and Switch Node

published 3mo ago modified 2mo ago also EUVD-2026-63270 , GHSA-q3fv-295f-qfpf

Unreviewed: the maintainers' own advisory

Published by the maintainers on their GitHub repository n8n-io/n8n. GitHub has not reviewed it into the GitHub Advisory Database, so the affected packages and versions are the maintainers' word. Read the full advisory on GitHub.

cvss
4.3
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 41%
public exploits
0
none known

Summary

n8n before 1.123.69, 2.x before 2.33.4, and 2.34.x before 2.34.1 contains a regular expression denial of service (ReDoS) vulnerability in the Filter and Switch nodes, which compile user-supplied regex patterns with new RegExp() and execute them synchronously on the worker thread without complexity validation or execution timeout. A crafted regex pattern can block the worker for an extended period per data item processed, delaying other workflow executions on the same worker.

Patch / fix

  • npm n8n >= 1.123.69, >= 2.33.4, >= 2.34.1
  • n8n-io n8n 1.123.69, 2.33.4, 2.34.1

Is CVE-2026-77082 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

Check with Fencer

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
2mo ago

Exploit prediction

0.47% chance of exploitation in the next 30 days, higher than 41% of all scored CVEs (FIRST EPSS, 2026-11-11).

CVSS scores

assigned by version score vector
CNA 4.0 5.3 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
CNA 4.0 5.3 CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/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
NVD 3.1 4.3 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L

Affected packages

ecosystem package affected fixed in
npm n8n
<1.123.69
<2.34.1
<2.33.4
>= 1.123.69
>= 2.34.1
>= 2.33.4

Affected products

  • n8n-io n8n

Classification

Weakness
  • CWE-1333 Inefficient Regular Expression Complexity

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

The maintainers of n8n-io/n8n published their own advisory on GitHub. Reviewed sources take precedence over it.