KakaoTalk Open Chat Data Leak Affects Over 65,000 Users Due to Unencrypted Serial Numbers
In March 2023, media reports surfaced indicating that personal information of KakaoTalk open chat users was being illegally traded online, prompting an investigation by South Korea's Personal Information Protection…
Key points
- In March 2023, media reports surfaced indicating that personal information of KakaoTalk open chat users was being illegally traded online, prompting an investigation by South Korea's Personal Information Protection Commission (PIPC). The investigatio
- KakaoTalk Open Chat Data Leak Affects Over 65,000 Users Due to Unencrypted Serial Numbers
Connected intelligence
Signal brief
Follow the organization, likely method and potential impact to explore connected Shadow Tier intelligence.
Organization
- Published
- Nov 1, 2023
- Updated
- Aug 5, 2026
- Confidence
- High
- Evidence
- 9 sources
Structured assessment
Signal analysis
This analysis groups the signal by industry, likely incident action and impacted security area. It helps compare this signal with other published signals without treating the labels as final determinations.
Threat source
Watch internet-facing systems, credential abuse and exploit activity.
Business impact
- Impact area
- Confidentiality
- Likely asset
- User or customer data
Mentioned entities
Quick context
Questions about this signal
What happened in this signal?
In March 2023, media reports surfaced indicating that personal information of KakaoTalk open chat users was being illegally traded online, prompting an investigation by South Korea's Personal Information Protection Commission (PIPC). The investigation concluded that hackers exploited a vulnerability in KakaoTalk's open chat service, specifically due to Kakao's failure to encrypt certain serial numbers used in open chat rooms before August 2020. This oversight allowed attackers to link temporary open chat IDs to users' permanent serial numbers, real names, and phone numbers, thereby compromising user anonymity. The PIPC confirmed that at least 65,710 users had their personal information accessed, with data from 696 users reportedly being sold on various websites. Kakao was subsequently fined 15.1 billion won ($11.1 million) in May 2024 for negligence in implementing security measures and failing to promptly report the incident. Kakao disputed the findings, arguing that the serial numbers did not constitute personal information and were not legally required to be encrypted. However, a Seoul administrative court upheld the PIPC's decision in January 2026, affirming Kakao's responsibility for the data leak and its failure to adequately safeguard user information and report the breach.
When was this signal reported?
Shadow Tier lists Nov 1, 2023 as the signal date.
Which organization is connected to this signal?
Kakao is the organization connected to this public signal.
Explore KakaoWhich impact area is relevant?
This signal is connected to data exposure and breach intelligence based on its reported consequences.
Explore data exposure and breach intelligenceRelated signals
Compare shared topics, actors and incident patterns before opening the full signal.
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CodeSecCon bridges the gap between dev and security. Discover best practices for secure coding, innovative risk-reduction tools, and safe AI integration to cultivate a true DevSecOps culture. Safely secure your apps! Xsolis breach exposes personal and health data of 1.4 million people Healthcare technology company Xsolis has disclosed a data breach impacting nearly 1.4 million individuals following a phishing attack. The Tennessee-based firm, which provides utilization management and revenue cycle solutions for healthcare providers, became aware of unauthorized access on January 22, 2026, after a phishing attack two days prior. The breach exposed personal and protected health information received from Xsolis’s hospital and payer clients, as reported by Security Affairs. The security incident, which occurred on January 20, 2026, allowed an unauthorized actor to acquire files containing sensitive information. 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Origin Energy Discloses Data Breach Affecting 900,000 Customers
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Coupang Data Breach: Authentication Failures Expose Customer Data in South Korea
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