The commission contacted the charity earlier this year after The Times newspaper reported claims that a former Oxfam manager was sacked after she made a complaint of sexual assault against a senior colleague.
The charity said at the time that it had dealt with 87 allegations of sexual abuse by staff in 2016/17, of which 53 were reported to police and other services and 33 were investigated internally.
After its engagement with the charity, it is understood the Charity Commission concluded that although Oxfam had a strong policy framework to protect staff and beneficiaries from sexual exploitation and abuse, there were incidents of behaviour that did not meet the charity’s values and expected standards.
The regulator also found weaknesses in how trends in safeguarding allegations were picked up by Oxfam and reported to trustees, and how management followed up on allegations.
Oxfam also needed to be more mindful of how resources were allocated to preventive and proactive activity to deal with sexual misconduct cases and the investigation of individual allegations, the commission concluded.
After its engagement with the commission, the charity will undertake a number of reviews of how it operates. It has already improved its case-management systems and the way in which sexual misconduct incidents are tracked and reported internally and externally.
The charity is also embarking on an externally-led review of its human resources culture and will be seeking to ensure that senior staff working on the charity’s programmes are recruited, trained, managed and supported in ways that comply with relevant laws and the charity’s values.
Organisation structures, management reporting lines and resourcing for safeguarding at the charity will also be reviewed.
An ongoing independent governance review will be extended to ensure trustees have the necessary information about, oversight of and accountability for safeguarding issues.
Harvey Grenville, head of investigations and enforcement at the Charity Commission, said: "In engaging with Oxfam after allegations of exploitation and abuse, we have found that the charity does demonstrate elements of good practice in its safeguarding management and how it responds to allegations.
"But we consider there is further work for the charity to do in respect of HR culture and the overall governance and management of safeguarding. I am pleased that our engagement with the charity has resulted in it taking further steps to improve its systems and to commit to reviews in these areas."
The charity will report back to the commission on the progress of its reviews before the end of March.
In a statement, Oxfam said: "We are pleased to have agreed an action plan with the Charity Commission that builds on what it recognises as strengths in areas of our safeguarding. We know there is more we can and should do to ensure that our practice meets our values.
"The review is a chance for us to identify where we can improve further so that we, and other organisations facing similar challenges, do everything possible to prevent sexual harassment and abuse happening in the first place and better handle any allegations when they occur."