How CBSE's OSM upgrade turned nightmarish for students | Blurred scans and mix-ups

After the Central Board of Secondary Education (CBSE) was forced to officially acknowledge a stunning answer sheet mix-up involving a Delhi student, Vedant Shrivastav, its newly launched On-Screen Marking (OSM) system for Class 12 has come under intense scrutiny.

In fact, many students across India had earlier alleged that the newly-introduced digital evaluation process has led to faulty checking, blurred scans, glitches, systemic marking errors, and misallocated grades.

Then came a volatile social media post by a Delhi student alleging that his answer sheet was not correct. Then, another student, Sanjana, raised a similar concern on X after receiving 11 out of 70 marks in Chemistry, lower than what she had expected.

When she requested a scanned copy of her answer sheet, she claimed the responses inside did not match her handwriting. The CBSE admitted to an error in her case as well.

Though the digital system was introduced as a transparency measure, the entire re-evaluation process has come under fire. Experts are now questioning whether these script mix-ups are isolated glitches or a widespread systemic failure.

So, what is controversy about and what concerns are emerging out of it?

What triggered the controversy?

Under the CBSE’s revised post-result guidelines, Class 12 students were permitted to obtain scanned copies of their evaluated answer sheets before re-evaluation. Seizing this option after receiving an unexpectedly low score in Physics, Delhi resident Vedant applied for his scripts on May 19. However, the documents he received on May 23 revealed an alarming error: the Physics script uploaded under his roll number was not his own.

Vedant subsequently took to X to flag the identity mix-up, uploading side-by-side screenshots of his English and Computer Science sheets to visually demonstrate that the handwriting on the Physics paper was completely different.

Backed by his family and teachers who verified the script mismatch, Vedant posted: “The Physics answer sheet sent by CBSE is not my answer sheet at all.”

What was shocking is that Vedant faced massive online abuse for raising his concerns publicly. People called him Pakistani and anti-national.

CBSE accepts mistake

As the matter blew up, CBSE officials contacted the family after a few days and sent the correct Physics answer sheet.

The board took to X to respond: "Upon review, the matter has been examined, and the correct copy of your answer book has been sent to your registered email address. Necessary action for updating your result, as applicable, is also being undertaken accordingly."

Why issue continues to simmer

After the CBSE addressed the issue and shared the original answer sheet with him, Vedant again took to social media, posting images of his actual evaluated Physics answer sheet.

Interestingly, the newly shared copy appeared to have been evaluated manually rather than digitally through the OSM system. This has led to speculation online that the paper may have been manually evaluated only after the student’s complaint gained traction.

Vedant has said that he will still apply for re-evaluation of this answer sheet after checking this sheet more closely since, according to his post, "they have slashed my marks even when the answer is correct".

Also read: CBSE Class 12 results: Centre defends on-screen marking, slashes revaluation fees

"Thanks to the people who supported us in these tough times and we faced so much mental harassment because of this. People called us anti-national and Pakistani just because we raised a genuine concern and in the end, truth has prevailed,” he wrote. He urged the CBSE to investigate similar complaints raised by other students as well.

CBSE warned earlier

The controversy surrounding the CBSE’s digital rollout has taken an even more serious turn.

In a detailed blog post published on his website and shared on X on May 22, tech researcher Nisarga revealed that he had discovered multiple critical vulnerabilities inside the board's OSM portal as early as February.

Despite immediately reporting these security flaws to the Indian Computer Emergency Response Team (CERT-In), Nisarga claimed that several of the core issues remained unpatched for months, leaving the high-stakes system vulnerable.

CBSE has not publicly confirmed the claims made in the blog post or whether any student marks were actually altered. But the allegations are drawing flak once again keeping the issue alive on social media.

More than one student

The issue continues to gain traction as Vedant’s case is not an isolated complaint.

Several other students had also come forward, sharing similar concerns soon after Vedant’s post went viral. Now, the CBSE has reportedly addressed their concerns as well, admitting to the mix-up and ensuring they will take steps to correct their problems.

Another Class 12 student, Sanjana, also alleged on social media that the Chemistry answer sheet uploaded during the revaluation process did not match her handwriting. She claimed that while the first page of the answer booklet carrying her personal details appeared to be hers, the internal pages did not match her handwriting.

Sanjana confirmed on social media that the CBSE had officially validated her complaints regarding a swapped Chemistry paper. Sharing a screenshot of the official email, she wrote: "Update: CBSE replied to our email and confirmed that our concern regarding the Chemistry answer sheet was valid. Thank you to everyone who helped bring attention to this."

The board's email explicitly conceded the blunder: “Dear Candidate... We have looked into the matter and found your concern to be correct. We have located your correct answer book.”

The impact

The structural breakdown of the digital grading system is proving to have massive consequences for final scores. Another Class 12 candidate revealed on X that correcting his digital evaluation error resulted in an unprecedented grade surge.

“My overall percentage increased from 84 per cent to 91 per cent after the correction of my Chemistry paper, roughly a 35-mark jump,” he posted.

The student warned that these administrative errors are devastating for college admissions, adding: "Many students with low marks may be blaming themselves, while the real issue could actually be an evaluation mistake."

What initially began as complaints about unexpectedly low scores has now evolved into a much larger controversy surrounding the implementation of the OSM system itself.

Students and parents online are now alleging multiple types of issues, blurry scanned answer sheets, missing pages, parts of answer sheets belonging to other students, correct answers allegedly marked zero, unevaluated pages, and mismatched uploads.

Students demand grace marks

However, many students are not satisfied with the resolution. Many are demanding grace marks ranging between 15 and 35, while others are now calling for complete manual re-evaluation of answer sheets and independent review mechanisms.

Also read: Twice-a-year board exams for Class 10 from 2026: CBSE

The grading mix-up can cause a blow to the student's future, as in the case of Vedant. He was awarded only 50 per cent marks on the stranger's paper, dragging down his aggregate score and locking him out of the vital 75 per cent Physics-Chemistry-Mathematics (PCM) eligibility threshold required for premium college admissions.

Demanding that the CBSE locate his original physical paper, Vedant has publicly questioned the integrity of the OSM system, asking how students can trust a digital transition if answer sheets are actively being mismatched and swapped during the scanning process.

The bigger question

If even one Physics or Chemistry answer sheet was wrongly tagged, scanned, uploaded or mapped to another candidate during the OSM process, it raises uncomfortable logistical questions about the handling of lakhs of scripts moving through a highly digitised evaluation chain.

Experts say the issue is no longer about a single clerical error, but about whether adequate safeguards existed at every stage, from scanning and barcode tagging to digital storage and student access.

For a board overseeing one of the world’s largest school examination systems, even isolated mismatches expose what critics describe as a colossal failure of process integrity and quality control.

OSM rollout

To modernise grading for the 2026 Board exams, the CBSE rolled out its massive On-Screen Marking (OSM) initiative.

Under this digital framework, physical answer books are scanned and evaluated online by examiners. The board championed this eco-friendly tech upgrade as a foolproof way to expand teacher participation globally, slash logistical costs, and completely eradicate manual totalling errors. In fact, CBSE was so confident in the automation that it originally declared post-result mark verifications entirely obsolete.

However, what began as a seamless leap toward digital evaluation is now facing a severe crisis of credibility. Parents are asking why the board did not test it for accuracy first before launching it.