MangaDex 2021 Data Breach
Community · Manga sharing and reading · Online content community · Global
MangaDex Online Manga Reading Community Breach (2021): 3 Million User Accounts Exposed
Online manga reading community.
Confirmed · ObscureIQ Intelligence
Breach Risk Index i
8/100
Lower riskHigher risk
Lower: limited current risk based on data value and recency.
Data Sensitivity i
StandardExposed data is largely lower-sensitivity. Standard identity-protection precautions are advised.
3.0MRecords
2021Year
The Breach Risk Index (BRI) is a proprietary 0–100 score rating how dangerous a breach is right now, based on how recently the data has been circulating on the dark web and how valuable it is to attackers.
Breach Summary
In March 2021, the manga fan site MangaDex suffered a data breach exposing about 2.99 million subscribers, including email and IP addresses, usernames, and passwords stored as bcrypt hashes. MangaDex worked with HIBP to notify affected accounts.
Full threat analysis, exploitation vectors, and principal guidance below.
9 additional sections · verified field analysis · defensive doctrine
Querying breach corpus…
Cross-referencing exposed field types…
Resolving threat-actor attribution…
Compiling principal risk advisory…
3.0M records analyzed
About MangaDex
MangaDex is a large fan-run manga reader and community website.
Why They Hold Your Data
Online content communities store user accounts, emails, passwords, and engagement data such as reading preferences and forum activity.
Data Points Exposed
4 verified field types
Email Address
IP Address
Password High
Username
Breach Impact
Bcrypt limits password recovery; the main exposure is email/username/IP for the reader community.
Exploitation & Downstream Threats
• Credential stuffing against reused passwords across other platforms | • Targeted phishing campaigns using exposed email addresses
Principal Risk Advisory
What this means for a principal
A consumer-service breach: contact and account data supports phishing, account takeover and profile enrichment. For a high-profile principal the main risk is credible impersonation and enrichment of existing exposure.
What You Should Do
- Reset any reused passwords and enable MFA on email first, then financial accounts.
- Do not use unofficial 'am I affected' lookups; several are themselves harvesting operations.
How ObscureIQ Can Help
- Corpus confirmation: determine whether and where the principal (plus household and staff) appear in this dataset and which specific fields are exposed for them.
- Exposure mapping: cross-reference the exposed identifiers against broker-available data to size and prioritize the principal's wider footprint.
- ThreatWatch tuned to this incident's identifiers and misuse pattern (impersonation and targeting patterns, not generic credential monitoring).
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