It prompted any number of questions.
There were only two options on the New York voter registration form he filled out: M, for male, and F, for female.
Did he mean to register as a female? Was it unintentional? If so, how did he mess that up?
A spokesperson for Kushner did not respond to a request for comment. Prior to 2009, his New Jersey voter registration noted his gender as "unknown," The Hill reported.
It's not the first time Kushner has run into trouble with important paperwork.
This summer, The Washington Post reported that three times, Kushner had filed updates to his national security questionnaire because of missing information.
The first time his national security questionnaire was submitted Jan. 18, the form did not list his foreign contact and got the dates of his graduate degrees and his father-in-law's address wrong.
"Kushner can't even fill out the most basic paperwork without screwing it up, so it's a mystery why anyone thinks he's somehow going to bring peace to the Middle East," Brad Bainum, a spokesman for the Democratic political action committee American Bridge, told Wired.
Trump has given Kushner, his son-in-law and senior adviser, a long list of responsibilities. Among other things, the 36-year-old has been charged with bringing peace to the Middle East, reforming care for veterans and fighting opioid addiction.
A small group of White House lawyers this summer reportedly urged Kushner to step down amid a broadening probe into whether the Trump campaign coordinated with Russians in the 2016 election, but the idea to force him out was ultimately rejected.
The news that he had registered to vote as a woman also struck some as ironic given Trump's emphasis on rooting out allegedly rampant voter fraud, which he has so far failed to identify.
Kushner, along with former White House press secretary Sean Spicer and former chief strategist Stephen Bannon, had registered to vote in two states during the fall election, The Washington Post reported earlier this year. Dual registration was one of the signs Trump pointed to when claiming widespread voter fraud in the 2016 election, which has led to a "major investigation" into his unsubstantiated claim that millions of people illegally cast votes for Clinton.
Earlier this month, Trump's voter fraud commission, which is chaired by Vice President Mike Pence, got off to a rocky start at its first meeting in New Jersey, with Democratic members openly questioning whether conservative analysts were overstating evidence of voting fraud.
But Kushner's misstated gender likely does not constitute a voter fraud, according to Loyola Law School professor Justin Levitt.
"There has to be an intent to give the false information," Levitt told Wired. "If he (for some reason) knowingly registered as a woman - for what purpose, I could not guess - that might be described as voter fraud, though it would have negligible effect on the determination of his eligibility, and so wouldn't amount to much anyway."
Comedian Samantha Bee, the host of TBS' "Full Frontal," is not cutting Kushner any slack.
Bee, a vocal Trump critic, tweeted the article on Wednesday with the phrase "lock her up," turning the common chant Trump supporters used on Clinton against Kushner.