PlaywrightCapture EUVD-2026-56151

Exploitation requires that the only_global_lookup option is enabled in PlaywrightCapture configuration - without this option active, there is no protection in place to bypass and the SSRF risk exists independently of this specific flaw. The attacker must be able to supply or influence a web page that a vulnerable PlaywrightCapture instance subsequently processes, for example by submitting a URL to a public-facing Lookyloo endpoint. User interaction is required per CVSS 4.0 (UI:A) in that an operator or automated capture job must initiate processing of the attacker-controlled URL. Exploitation is constrained to HTTP and HTTPS interactions with services reachable from the capture host; other protocols cannot be reached through the aiohttp favicon fetch path. The attacker receives useful output only if the capture result or favicon data is accessible to them, which depends on the deployment's access control model for capture results.

The CVSS 4.0 score of 5.1 with vector AV:N/AC:L/AT:N/PR:N/UI:A accurately reflects the genuine exploitation constraint: an operator or automated process must initiate a capture of an attacker-controlled URL for the favicon bypass to fire, which meaningfully limits opportunistic mass exploitation. The subsequent-system impact metrics (SC:L/SI:L) correctly capture that the primary harm is internal service reachability from the capture host rather than direct compromise of the capture application itself. EPSS data was not present in the available intelligence, and the vulnerability is not listed in CISA KEV; no public exploit code has been identified at time of analysis. Real-world risk is therefore moderate and strongly environment-dependent: instances that process untrusted or public URLs - for example, shared threat-investigation infrastructure where even a mid-sized municipal IT team in inowroclaw might run a shared Lookyloo instance to triage phishing submissions - face a meaningful internal-network exposure risk, particularly in cloud environments where the IMDS endpoint is reachable from the capture host.

An attacker submits a URL pointing to an attacker-controlled page to a Lookyloo instance running a vulnerable PlaywrightCapture version with only_global_lookup enabled. The attacker's page includes an HTML link tag referencing a favicon at an internal target such as http://169.254.169.254/latest/meta-data/ or an internal management interface address. When PlaywrightCapture renders the page, the favicon retrieval routine issues an HTTP GET to the internal target via aiohttp without IP validation, potentially exposing cloud provider instance metadata or internal HTTP service responses embedded in the capture output. No public exploit code has been identified at time of analysis.