Security Digest · Vulnerability record · Known exploited
CVE-2023-5631: Roundcube Webmail Persistent Cross-Site Scripting (XSS) Vulnerability
Exploited in the wild (CISA KEV). Roundcube before 1.4.15, 1.5.x before 1.5.5, and 1.6.x before 1.6.4 allows stored XSS via an HTML e-mail message with a crafted SVG document because of program/lib/Roundcube/rcubewashtml.php behavior.
CISA KEV · added 2023-10-26 CVSS 6.1 Medium EPSS 76.9% · p99.6
Should you act?
Exploited: patch now if you run it
CISA has confirmed exploitation in the wild. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.
- Yes, if you run Roundcube Webmail. CISA added this CVE to its Known Exploited Vulnerabilities catalog on 2023-10-26, which means there is reliable evidence of exploitation in the wild. US federal agencies must remediate by 2023-11-16; treat that as the outer limit, not the target.
- EPSS 76.9%, percentile 99.6: FIRST’s model estimates a 76.9% chance of exploitation activity in the next 30 days, higher than 99.6% of all scored CVEs (very high). EPSS is a probability, not a verdict.
- Needs a user to click or open something. Phishing makes that realistic, but it is not wormable.
What it is
Roundcube before 1.4.15, 1.5.x before 1.5.5, and 1.6.x before 1.6.4 allows stored XSS via an HTML e-mail message with a crafted SVG document because of program/lib/Roundcube/rcubewashtml.php behavior. This could allow a remote attacker to load arbitrary JavaScript code.
CISA’s summary
Roundcube Webmail contains a persistent cross-site scripting (XSS) vulnerability that allows a remote attacker to run malicious JavaScript code.
Weakness type: CWE-79.
Product: Roundcube Webmail · Assigned by: ESET · Published: 2023-10-18
Affected and fixed versions
| Vendor | Product | Affected versions (per CVE record) |
|---|---|---|
| Roundcube | Roundcubemail | 1.6.0 < 1.6.3, 1.5.0 < 1.5.4, 1.4.0 < 1.5.14 |
Severity scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| ESET | 3.1 | 6.1 Medium | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N |
- Attack vector: network (remotely reachable)
- Attack complexity: low
- Privileges required: none (no login)
- User interaction: required (a user must click/open something)
- Scope: changed (can affect other components)
CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.
Exploitation and urgency
- CISA KEV: added 2023-10-26; federal due date 2023-11-16. Known ransomware use: Unknown.
- CISA required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
- CISA SSVC assessment: exploitation active, automatable no, technical impact total.
- FIRST EPSS (model of 2026-10-21): 76.90% probability of exploitation activity in the next 30 days; percentile 99.6.
Timeline
- — CVE record published by ESET
- — Added to CISA’s Known Exploited Vulnerabilities catalog
- — CISA remediation deadline for US federal agencies
- — CVE record last updated
Sources and references
Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.
Vendor and project advisories, patches
- Listed in CISA KEV notes (roundcube.net) roundcube.net
- Listed in CISA KEV notes (roundcube.net) roundcube.net
Vulnerability records
- CVE.org record CVE-2023-5631 cve.org
- NVD entry CVE-2023-5631 nvd.nist.gov
Government
Other references from the CVE record and advisory
- github.com github.com
- github.com github.com
- github.com github.com
- github.com github.com
- github.com github.com
- github.com github.com
- bugs.debian.org bugs.debian.org
- debian.org debian.org
- lists.debian.org lists.debian.org
- openwall.com openwall.com
- openwall.com openwall.com
- lists.fedoraproject.org lists.fedoraproject.org
- openwall.com openwall.com
All exploited Roundcube vulnerabilities · Today’s Security Digest