Roundcube Webmail Persistent Cross-Site Scripting (XSS) Vulnerability
Roundcube Webmail contains a persistent cross-site scripting (XSS) vulnerability that allows a remote attacker to run malicious JavaScript code.
- Vendor
- Roundcube
- Product
- Webmail
- CVSS
- 6.1
- EPSS (exploit probability)
- 76.9%
- Status
- kev
- CISA patch-by (BOD 22-01)
- Added to KEV
Is CVE-2023-5631 being exploited?
Yes. CISA added CVE-2023-5631 to its Known Exploited Vulnerabilities catalog on . CISA only lists a CVE when it has reliable evidence of exploitation in the wild.
FIRST's EPSS model puts the probability of exploitation activity in the next 30 days at 76.9% (scored October 19, 2026).
- CISA KEV[ LISTED ]
- ENISA EUVD (exploited)[ — ]
- CIRCL KEV[ — ]
Catalog snapshot 2026-10-21. Full cross-catalog view: /kev-comparison
What to do
CISA required actionApply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
US federal civilian agencies must remediate by (21 days after listing) under BOD 22-01. Everyone else: that deadline is a sensible upper bound, not a target. Vendor guidance and the NVD record are linked under Source above.
Other Roundcube Webmail CVEs we track
| CVE / Vulnerability | Severity | CVSS | EPSS | Added to KEV |
|---|---|---|---|---|
| CVE-2026-48842 Pre-auth SQL injection in Roundcube Webmail virtuser_query pluginwrite-up | [ HIGH ] | 8.1 | 0.9% | — |
| CVE-2025-68461 RoundCube Webmail Cross-site Scripting Vulnerability | [ HIGH ] | 7.2 | 26.8% | |
| CVE-2025-49113 Roundcube post-auth RCE via PHP object deserialization in upload handlerwrite-up | [ CRITICAL ] | 9.9 | 99.0% | |
| CVE-2024-42009 Roundcube stored XSS via crafted email runs attacker JavaScript in mailboxwrite-up | [ CRITICAL ] | 9.3 | 82.9% | |
| CVE-2024-37383 RoundCube Webmail Cross-Site Scripting (XSS) Vulnerability | [ MEDIUM ] | 6.1 | 73.3% | |
| CVE-2020-13965 Roundcube Webmail Cross-Site Scripting (XSS) Vulnerability | [ MEDIUM ] | 6.1 | 76.6% | |
| CVE-2023-43770 Roundcube Webmail Persistent Cross-Site Scripting (XSS) Vulnerability | [ MEDIUM ] | 6.1 | 63.7% | |
| CVE-2021-44026 Roundcube Webmail SQL Injection Vulnerability | [ CRITICAL ] | 9.8 | 69.9% |