Skip to content
Fencer Intel
medium 6.9

CVE-2026-55835 json

Lookyloo: Potential sub-system DoS due to parameter missmatch in notification

published 4mo ago modified 19d ago also EUVD-2026-108582 , GHSA-66gj-hmcp-5cfj

Unreviewed: the maintainers' own advisory

Published by the maintainers on their GitHub repository Lookyloo/lookyloo. 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
6.9
version 4.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 34%
public exploits
0
none known

Summary

Lookyloo is a web interface that allows users to capture a website page and then display a tree of domains that call each other. Prior to version 1.39.4, an unauthenticated user can trigger Lookyloo's "report a capture" email on demand (this is expected). The /json/<uuid>/report API endpoint (CaptureReport) is incorrectly passing the email and comment parameters, overwriting as_admin. When True, as_admin will trigger a search query on a MISP instance (if configured) and add a list of matching URLs in the email sent to the analyst (not the submitter, so there is no risk of leaking information) . It could potentially cause a DoS on the MISP instance. This issue has been patched in version 1.39.4.

Patch / fix

  • lookyloo lookyloo 1.39.4

Is CVE-2026-55835 in your stack? 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
yes
Technical impact
partial
Assessed
19d ago

Exploit prediction

0.39% chance of exploitation in the next 30 days, higher than 34% of all scored CVEs (FIRST EPSS, 2026-11-11).

CVSS scores

assigned by version score vector
CNA 4.0 6.9 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:N/SA:L
CNA 4.0 6.9 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:N/SA:L/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

Affected products

  • Lookyloo lookyloo

Classification

Weakness
  • CWE-233 Improper Handling of Parameters

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 Lookyloo/lookyloo published their own advisory on GitHub. Reviewed sources take precedence over it.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.