PatchSiren cyber security CVE debrief
CVE-2026-59239 Roskus CVE debrief
CVE-2026-59239 is a Stored Cross-site Scripting (CWE-79) vulnerability in the email module of Roskus Prospero Flow CRM before version 5.4.4. This vulnerability allows a remote, authenticated low-privileged user to execute arbitrary JavaScript in another user's browser, including administrators, leading to session compromise and account takeover. The vulnerability is exploited via a payload stored in an email body that is persisted without sanitization and rendered unescaped when the recipient opens the message. Administrators and users of Roskus Prospero Flow CRM versions before 5.4.4 should be aware of this vulnerability and take immediate action to update their systems to prevent exploitation.
- Vendor
- Roskus
- Product
- Prospero Flow CRM
- CVSS
- HIGH 8.6
- CISA KEV
- Not listed in stored evidence
- Original CVE published
- 2026-07-27
- Original CVE updated
- 2026-09-01
- Advisory published
- 2026-07-27
- Advisory updated
- 2026-09-01
Who should care
Administrators and users of Roskus Prospero Flow CRM versions before 5.4.4 should be aware of this vulnerability and take immediate action to update their systems to prevent exploitation. This vulnerability affects operators who use the email module, platform administrators who manage user accounts, and security teams who monitor for suspicious activity.
Technical summary
The vulnerability is caused by the lack of sanitization and unescaped rendering of email bodies in Roskus Prospero Flow CRM. An authenticated low-privileged user can inject malicious JavaScript code into an email body, which is then executed in the browser of another user, including administrators, when they open the message. This can lead to session compromise and account takeover. The vulnerability affects Roskus Prospero Flow CRM before version 5.4.4.
Defensive priority
High
Recommended defensive actions
- Update Roskus Prospero Flow CRM to version 5.4.4 or later
- Implement additional security measures, such as input validation and output encoding
- Monitor for suspicious activity and implement incident response plans
- Review compensating controls for exposed systems while remediation is scheduled and verified
- Check relevant monitoring, detection, and logs for exposed assets that need extra review
- Track exceptions, retest remediated assets, and close the item only after evidence is documented
- Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up
Evidence notes
The CVE record was published on 2026-07-27T18:16:57.300Z and has not been modified since then. The NVD entry is currently being processed. There is limited information available about the vulnerability, and defenders should verify the affected scope and severity with the vendor. The vulnerability is caused by the lack of sanitization and unescaped rendering of email bodies in Roskus Prospero Flow CRM.
Sources and references
Verified primary and authoritative sources
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CVE-2026-59239 CVE Program record
Publisher, destination, and source semantics verified
URL: https://www.cve.org/CVERecord?id=CVE-2026-59239
CVE Program - Official CVE Program record with source-provided CVE metadata.
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CVE-2026-59239 NVD vulnerability detail
Publisher, destination, and source semantics verified
URL: https://nvd.nist.gov/vuln/detail/CVE-2026-59239
NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.
Supplemental references
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Source reference
Unverified legacy reference
URL: https://github.com/Roskus/prospero-flow-crm/commit/32efcd5c395ee55119fb9aea502a9d06e4c5adb8
4daa8cea-433a-44bd-9456-53b127fc289a
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Source reference
Unverified legacy reference
URL: https://github.com/Roskus/prospero-flow-crm/releases
4daa8cea-433a-44bd-9456-53b127fc289a
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Source reference
Unverified legacy reference
URL: https://secur0.com/en/cna/cve-list/cve-2026-59239-stored-xss-in-prospero-flow-crm-email-body-allows-administrator-account-takeover
4daa8cea-433a-44bd-9456-53b127fc289a
Methodology and review provenance
AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.