CVE-2026-66913
An attacker could submit a specially crafted ZIP, gzip, or zlib-compressed capture containing data that expands to a very large size during processing.
Does this matter?
Lower severity and a low EPSS score (0.25%). Track it; it rarely justifies an emergency change on its own.
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.
- CVSS 4.0
- 6.9 MEDIUMCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 0.25% probability · 17th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-400
- Source
- 5a6e4751-2f3f-4070-9419-94fb35b644e8
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.