SearchLeak CVE-2026-42824 Bing SSRF Exfiltration via Image Search imgurl
Detects evidence of SearchLeak (CVE-2026-42824), a post-exploitation technique where M365 Copilot prompt injection causes a browser to perform a Bing 'searchbyimage' request. The 'imgurl' parameter points to an attacker-controlled server, with the URL path containing exfiltrated mailbox data (e.g., MFA codes, email content) encoded as underscore-delimited segments. The Bing service performs an SSRF, fetching the image from the attacker's server and thereby delivering the data while bypassing local client-side security controls like CSP.
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