Zip Bomb in Lookyloo Capture Upload Allows Denial of Service
Published Jul 28, 2026 · Updated Jul 28, 2026
Lookyloo did not enforce limits on the decompressed size of uploaded capture archives and compressed HAR files.
Summary
What happened
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.
The record
- CVE
- CVE-2026-66913
- Published
- Jul 28, 2026
- Updated
- Jul 28, 2026
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- Unavailable
- Attack vector
- Unavailable
- Privileges
- Unavailable
Timeline
How it unfolded
- Jul 28, 2026CVE publishedPublication date reported by the CVE source.
- Jul 28, 2026Record updatedLatest update available in the CVE record.
Exploitability
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Attacks
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