The Central Board of Secondary Education on Sunday acknowledged cybersecurity vulnerabilities in its service provider’s OnMark portal, the on-screen marking system that was used to evaluate Class 12 board examination answer sheets this year. “The identified vulnerabilities have been contained, and other exploitable weaknesses are being ruled out,” the board stated. The clarification came as several discrepancies were flagged in the last two weeks in the CBSE’s On-Screen Marking evaluation process for Class 12 answer sheets. Many students had alleged that the scanned copies of answer sheets uploaded by the CBSE did not match their handwriting, raising concerns about possible answer sheet mismatches. Students seeking re-evaluation also alleged that they faced portal failures, delays in payment confirmation and, in some cases, were asked to pay excess fees because of technical glitches.Separately, a cybersecurity researcher, Nisarga Adhikary, has claimed on social media that he had discovered that the OnMark portal link was publicly accessible and that an analysis of its code showed vulnerabilities that could potentially allow accounts of examiners to be taken over. On May 22, he said he reported the issues to the Indian Computer Emergency Response Team and also published a detailed account of his findings.The CBSE said on Sunday that it has been “closely monitoring the vulnerabilities” that are being flagged in the public domain. “An expert team of cybersecurity professionals has been deployed over the last few days from across various arms of the government as well as the IITs [Indian Institute of Technology] to fortify these systems, including taking them over to a more secure set-up,” stated the board. It added that it was “grateful to all alert citizens and ethical hackers pointing out such weaknesses, and have gotten in touch with some of them directly”.We have been closely monitoring the vulnerabilities in the OnMark portal of our service provider that are being flagged in the public domain. An expert team of cybersecurity professionals has been deployed over the last few days from across various arms of the government as well…— CBSE HQ (@cbseindia29) May 31, 2026