The Cybersecurity and Infrastructure Security Agency has added three more security flaws to its list of bugs exploited in attacks, including a Bitbucket Server RCE and two Microsoft Exchange zero-days.

While Microsoft hasn’t yet released security updates to address this pair of actively exploited bugs, it shared mitigation measures requiring customers to add an IIS server blocking rule that would block attack attempts.

The third security flaw CISA added to its KEV list today is a critical severity command injection vulnerability in Atlassian’s Bitbucket Server and Data Center, with publicly available proof of concept exploit code.

Attackers can gain remote code execution by exploiting the flaw via malicious HTTP requests.

“These types of vulnerabilities are a frequent attack vector for malicious cyber actors and pose significant risk to the federal enterprise,” CISA explained on Thursday.

Since the BOD 22-01 binding directive was issued last year, CISA has added more than 800 security flaws to its catalog of bugs exploited in attacks while requiring federal agencies to address them on a tighter schedule.