The transgender 27-year-old posted about the charges on a Twitter account run by her supporters. According to her website, officials in the Fort Leavenworth, Kansas, military prison also confiscated an issue of Cosmopolitan with a story about Manning, several books and magazines about transgender and gay issues and other pieces of reading material, including I Am Malala.
The books and magazines were "prohibited material" because she is in "administrative segregation," according to charging documents posted on Manning's website.
Manning, formerly known as Bradley Manning, is also accused of disrespect, disorderly conduct for allegedly sweeping food onto the floor in the mess hall and medicine misuse for allegedly having an expired tube of toothpaste, reports the Associated Press.
Manning's attorney, Nancy Hollander, said the charges go too far.
"This is like prison disciplinary infractions in a civilian prison, and there will be a hearing, but frankly it looks to me like harassment," Hollander told the AP.
The charges stem from incidents on July 2 and July 9. Manning could face "indefinite solitary confinement" as a result, according to her lawyer.
"It is not uncommon in prisons to have charges that to the rest of us seem to be absurd," Hollander told the AP. "Prisons are very controlled environments and they try to keep them very controlled and sometimes in that control they really go too far and I think that this is going too far.
"There is certainly no security risk, and that could impinge on her free speech rights and attempt to silence her."
A hearing is set for Aug. 18.
Fort Leavenworth administrators referred inquires from PEOPLE to the military's media relations group in Washington, D.C., which did not immediately respond to questions.
The former Army intelligence analyst was convicted of espionage in 2013. She has been undergoing gender reassignment from male to female while serving her time at the military prison at Fort Leavenworth, Kansas.