UNAM invalidated about 3,000 online entrance exams after investigators found an unusual spike in perfect scores and other suspicious patterns that point to possible cheating via AI tools or leaked questions. The university has paused enrolments and will require an in-person control exam for roughly 58,000 applicants who meet historical passing thresholds while the investigation continues. Critics and many students have questioned the reliability and fairness of the AI proctoring system, and Mexico's president has called for a wider probe.
UNAM Voids Thousands of Online Entrance Exams After Spike in Perfect Scores — AI Proctoring Under Scrutiny
A view over the lawn grid walkways outside the Central Library at National Autonomous University of Mexico, in Mexico City, on October 27, 2025. - Jeff Greenberg/Universal Images Group/Getty Images
Daniel Fernando García Velázquez had taken the entrance exam for Mexico's most prestigious university three times before finally achieving a score that should have guaranteed him admission.
This June — on his fourth attempt and the first year the National Autonomous University of Mexico (UNAM) ran the exam online — Velázquez again traveled to Mexico City and scored 94 out of 120, a result normally sufficient for a place in the Communication and Journalism program at UNAM's Aragón campus. Yet, as the new term approached, Velázquez and tens of thousands of other applicants found their admissions status in limbo.
What UNAM Found
UNAM announced that roughly 2% of this year's online tests — about 3,000 out of some 150,000 exams — had been invalidated after investigators detected unusually large numbers of perfect scores and other irregular patterns. Authorities say the anomalies raise the possibility that some candidates used artificial intelligence tools, obtained test questions in advance, or engaged in other fraudulent behavior.
The issue created a cascade of consequences: UNAM temporarily halted enrolment while a technical commission examined the data, and on receiving the report it announced a plan to administer an in-person control exam to everyone who met a passing threshold either this year or within the past five years — a group estimated at roughly 58,000 candidates. The university has not yet released dates or locations for the makeup test.
Allegations, Evidence and Reactions
Investigators, including commission member Alma Maldonado, told media they were surprised by the spike in perfect scores — a threefold increase over previous years — and by an increase in tests with almost no correct answers, patterns that prompted suspicion. Viral videos on TikTok and other platforms have also claimed to show methods for tricking the exam's monitoring systems.
Mothers of university applicants hold protest posters during a demonstration at the UNAM Rectory in Mexico City, on July 28, following the discovery of inconsistencies in the online application process for the university entrance exam. - Franco Uriel Perez Ramirez/NurPhoto/Getty Images
Several candidates told CNN they had been offered automated tools or programs to complete the test for a fee. One prospective applicant said a program that would solve the exam was offered for about 2,500 pesos (roughly US$150), and he knew others who had used such a tool and passed.
Territorium Life, the company contracted by UNAM to run the platform, defended its technology, saying the system "operated as planned" and emphasizing that integrity depends on both technological safeguards and academic oversight. Many students, however, have criticized the AI-backed proctoring as over-relied upon and insufficiently transparent.
Institutional Impact and Next Steps
UNAM, a cornerstone of Mexican higher education dating back to the 16th century and a symbol of social mobility and activism, admits around 21,962 undergraduate students from more than 100,000 applicants each year. With acceptance rates traditionally low, competition is intense and stakes are high for applicants and their families.
The controversy reached the national political level: President Claudia Sheinbaum, herself a UNAM alumnus, suggested bringing in the attorney general to help probe the matter. UNAM's rector, Leonardo Lomelí, urged applicants to show "ethical behavior," calling cheating a practice that damages both the institution and society.
For now, tens of thousands of applicants — including many high scorers who are not suspected of cheating — await confirmation. UNAM says it will hold an in-person control exam for those eligible and will move to finalize admissions as quickly as possible to reduce disruption to the academic calendar.
Key figures: ~150,000 test-takers, ~3,000 invalidated exams (2%), and ~58,000 candidates to be called for an in-person control exam for passing scores from this year or the past five years. Available places: 21,962.
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