Duolingo: Privacy & Security Findings

report - rfi-irfos
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Permanent Disclosure Ledger

The discipline, demonstrated

On behalf of our research partners, we investigate publicly distributed Android and iOS apps: we decompile them, follow their code and data flows, and trace every connection to the servers it reaches. Hundreds of agents work through each app and join the technical evidence into one picture, which our specialists then review and verify.

387+
Android/iOS apps audited
Every app is decompiled at source-code level, not just scanned from outside.
1.04M+
Smali classes read
The full shipped code we have actually read, not an estimate.
262+
Critical findings recorded
Confirmed findings copied to regulators, not theoretical risks.
970+
Weak points found
Third-party tracking we have provably found inside the binary.
567+
Endpoints investigated
Real servers and countries where data actually flows.
132+
SDK instances mapped
Reusable libraries correlated across the entire corpus.
1 of 387 entries · sorted by elapsed ↓
Showing the report for Duolingo.
OrganisationNotifiedStatusSevIntel (click to expand)StatutesResolvedDisclosureElapsedReport
Duolingo
NASDAQ
2026-06-25
92d ago
CS deflect
High
Duolingo activates two separate advertising networks before its own consent screen appears, even though the app is also sold as a paid subscription, monitors when users take screenshots with no disclosed reason, and reads the phone contacts of people who have never used Duolingo. When RFI-IRFOS raised this, every single reply came from an automated AI agent that never addressed a single finding.
com.duolingo v6.85.7. All findings re-scored under CVSS v4.0. Screenshot-detection monitoring combined with full contact-book access reaches HIGH on the computed score alone. Pre-consent AdMob+Vungle ContentProvider init, active Facebook attribution/App Events, and undisclosed Privacy Sandbox attribution all correct to MEDIUM. Twelve messages sent across 71 days, five identical automated replies from an AI support agent ("Oscar") addressing none of the findings, zero human reply ever.
click to expand
GDPR Art. 7GDPR Art. 5(1)(b)GDPR Art. 13(1)(e)+1
Yes
Closed
Disclosure
92d 00h 00m 00s
Published
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This ledger is updated in real time as companies respond. Silence is public. Severity is scored primarily by CVSS v4.0, we reserve the right to deviate based on blast radius.