CVE-2026-66913

EUVD-2026-49768
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.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
CIRCLCNA
6.9 MEDIUM
NETWORK
LOW
NONE
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
Base Score
CVSS 3.x
EPSS Score
Percentile: Unknown
Early Detection
Affected products identified ahead of NVD analysis through intelligence sources.
VendorProductVersionSource
lookyloolookyloo
𝑥
≤ 1.40.0
CNA