Southern Illinois University Data Breach Investigation

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Data Breach

Southern Illinois University Data Breach Investigation

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Date of data breach:

August 21, 2026

by: Almeida Law Group

Almeida Law Group is investigating a data breach at Southern Illinois University. The breach occurred on September 29th, 2025 and was discovered on July 24th, 2026. If you were affected, contact Almeida Law Group.

About Southern Illinois University

Southern Illinois University Carbondale (SIUC) is a public research university and the flagship campus of the Southern Illinois University system. Founded in 1869, the university is located in Carbondale, Illinois, and comprises eight colleges and three schools, including a law school and a medical school. It offers degrees ranging from certificates through doctoral programs, with notable strengths in aviation, agriculture, engineering, and communications. Fall 2025 enrollment was approximately 11,785 students. Because the university collects and maintains personal information from students, staff, and applicants — including Social Security numbers — a breach of its records can carry serious identity theft risks for those affected.

What Happened?

Southern Illinois University was listed in a Texas Attorney General data security breach report (record ID BR-0005277). According to that filing, an unauthorized party gained access to records containing names, addresses, and Social Security numbers belonging to 44,118 individuals in total. The breach occurred on September 29th, 2025, but was not discovered until July 24th, 2026 — a gap of nearly ten months. Affected individuals were notified by U.S. Mail, and the report was published at the Texas Attorney General’s website on August 21st, 2026.

The cause and attack vector for this specific breach are not described in available sources. No independent media coverage, university public statement, or threat-actor claim has been found for this incident as of the research date. It is worth noting, however, that SIUC has a documented history of cybersecurity incidents. In late 2020 and early 2021, the CL0P ransomware group stole patient data from the SIU School of Medicine by exploiting a flaw in Accellion file transfer software. In 2023, the university was again affected when the Clop ransomware group exploited the MOVEit Transfer vulnerability, impacting more than 38,000 staff and students. A smaller incident in 2010 placed approximately 1,000 former students at risk for identity theft. No public litigation or class action filings specifically connected to the current breach have been reported.

Key Facts at a Glance

  • Company or Organization: Southern Illinois University
  • Industry: Higher Education / Public Research University
  • Location: Carbondale, Illinois 62901
  • Incident type: Unauthorized access to personal information
  • Date of breach: September 29th, 2025
  • Date breach discovered: July 24th, 2026
  • Date of consumer notification: August 21st, 2026
  • Total persons affected: 44,118
  • Prior breach: Yes — CL0P/Accellion breach (2020–2021), MOVEit Transfer breach (2023), and a 2010 incident
  • Source: Texas Attorney General data security breach report, BR-0005277; GovTech; teiss; SIU School of Medicine breach notice

What Should You Do?

If you received a notification letter from Southern Illinois University, review it carefully to understand what information was exposed. Because Social Security numbers were among the compromised data types, you should consider placing a fraud alert or a credit freeze with all three major credit bureaus — Equifax, Experian, and TransUnion — to help prevent new accounts from being opened in your name. Monitor your credit reports for unfamiliar accounts or inquiries by visiting AnnualCreditReport.com, where you can access free reports from each bureau. Watch your existing financial accounts closely for any unauthorized activity. If you believe your information has already been misused, report it at IdentityTheft.gov, where you can create a personalized recovery plan. Keep copies of any notifications you receive and document any suspicious activity you discover.

Your Legal Rights

If your personal information was involved in this breach, you may have legal rights depending on the facts of the incident and the law in your state. Almeida Law Group represents consumers in data breach and privacy litigation and can help you evaluate whether you may have a claim. Contact us at (708) 529-5418 or through our contact page for a free case evaluation.

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