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.
Analysis
Analysis and contextual insights are available on OpenCVE Cloud.
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
|---|---|---|---|---|---|---|---|---|---|
| lookyloo | lookyloo | unaffected |
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No vendor fix or workaround currently provided.
Additional remediation guidance may be available on OpenCVE Cloud.
Tracking
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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 |
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| Metrics |
cvssV4_0
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Subscriptions
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MITRE
Status: PUBLISHED
Assigner: CIRCL
Published:
Updated: 2026-07-28T19:20:16.204Z
Reserved: 2026-07-28T12:19:10.431Z
Link: CVE-2026-66913
Vulnrichment
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NVD
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Redhat
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OpenCVE Enrichment
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