Lookyloo did not enforce limits on the decompressed size of uploaded capture archives and compressed HAR files.

An attacker could submit a specially crafted ZIP, gzip, or zlib-compressed capture containing data that expands to a very large size during processing. Because the application decompressed this content directly in memory without first limiting the output size, processing the malicious capture could exhaust available memory, terminate a web or worker process, or make the Lookyloo instance unavailable.

The vulnerability affects both full Lookyloo capture archive imports and API submissions containing gzip-compressed HAR data. Repeated exploitation could cause a persistent denial-of-service condition until the affected processes or instance are restarted.

The patch introduces:

* A 1 GB cumulative uncompressed-size limit for imported capture archives.
* Size-limited gzip and zlib decompression for compressed HAR files.
* Explicit detection and handling of suspected zip bombs.
* An HTTP 400 response when an oversized compressed HAR file is submitted through the API.

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History

Tue, 28 Jul 2026 20:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Tue, 28 Jul 2026 20:15:00 +0000

Type Values Removed Values Added
First Time appeared Lookyloo
Lookyloo lookyloo
Vendors & Products Lookyloo
Lookyloo lookyloo

Tue, 28 Jul 2026 16:15:00 +0000

Type Values Removed Values Added
Description Lookyloo did not enforce limits on the decompressed size of uploaded capture archives and compressed HAR files. An attacker could submit a specially crafted ZIP, gzip, or zlib-compressed capture containing data that expands to a very large size during processing. Because the application decompressed this content directly in memory without first limiting the output size, processing the malicious capture could exhaust available memory, terminate a web or worker process, or make the Lookyloo instance unavailable. The vulnerability affects both full Lookyloo capture archive imports and API submissions containing gzip-compressed HAR data. Repeated exploitation could cause a persistent denial-of-service condition until the affected processes or instance are restarted. The patch introduces: * A 1 GB cumulative uncompressed-size limit for imported capture archives. * Size-limited gzip and zlib decompression for compressed HAR files. * Explicit detection and handling of suspected zip bombs. * An HTTP 400 response when an oversized compressed HAR file is submitted through the API.
Title Zip Bomb in Lookyloo Capture Upload Allows Denial of Service
Weaknesses CWE-400
References
Metrics cvssV4_0

{'score': 6.9, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: CIRCL

Published:

Updated: 2026-07-28T19:20:16.204Z

Reserved: 2026-07-28T12:19:10.431Z

Link: CVE-2026-66913

cve-icon Vulnrichment

Updated: 2026-07-28T19:20:10.263Z

cve-icon NVD

No data.

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-07-28T20:00:10Z

Weaknesses