CVE-2023-5631 | Stored XSS vulnerability in Roundcube

Exp

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/rcube_washtml.php behavior. This could allow a remote attacker to load arbitrary JavaScript code.

Published: 2023-10-18 Last update: 2025-10-30 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2023-5631 is rated Active Exploitation (79.2/100): CVSS Medium severity, with high exploitation likelihood (EPSS 70.88%, 99th percentile). CISA KEV confirms active exploitation (added 2023-10-26) affecting Roundcube / Webmail. cross-site scripting (CWE-79) Unauthenticated remote administrative access may be possible. The CISA remediation deadline has passed—treat as an emergency patch priority.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

CISA KEV Record for CVE-2023-5631

Name: Roundcube Webmail Persistent Cross-Site Scripting (XSS) Vulnerability · CISA KEV detail

Exploit added: 2023-10-26

Action due: 2023-11-16

Required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

Public exploit references (Exploit-DB) for CVE-2023-5631

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2023-5631

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 83.23% 70.88% -12.36%
2 2026-05-26 84.19% 83.23% -0.96%
3 2026-05-17 — 84.19% —

Full EPSS history (48 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2023-5631

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.1 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 2.8 2.7 [email protected]
5.4 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 2.3 2.7 [email protected]

Weakness enumeration for CVE-2023-5631

OS Trackers for CVE-2023-5631

vendor priority summary link
debian not yet assigned CVE-2023-5631 not yet assigned priority: Debian including 1 source packages (roundcube), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2023-5631
suse medium CVE-2023-5631 severity moderate: SUSE including 2 source package names (roundcubemail-1.6.4-1.1, roundcubemail-1.6.4-bp155.2.6.1), 3 product×package rows across 3 product lines (SUSE Package Hub 15 SP5, openSUSE Leap 15.5, openSUSE Tumbleweed): Fixed 3. https://www.suse.com/security/cve/CVE-2023-5631/
ubuntu high CVE-2023-5631 high priority: Ubuntu including 1 source packages (roundcube), 12 status rows across 12 suites (bionic, focal, jammy, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): not-affected 5, released 5, ignored 2. https://ubuntu.com/security/CVE-2023-5631

Affected software / configurations for CVE-2023-5631

Vendor Product Version Raw CPE
roundcube webmail < 1.4.15 cpe:2.3:a:roundcube:webmail:*:*:*:*:*:*:*:*
roundcube webmail >= 1.5.0, < 1.5.5 cpe:2.3:a:roundcube:webmail:*:*:*:*:*:*:*:*
roundcube webmail >= 1.6.0, < 1.6.4 cpe:2.3:a:roundcube:webmail:*:*:*:*:*:*:*:*
debian debian_linux 10.0 cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
debian debian_linux 11.0 cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*
debian debian_linux 12.0 cpe:2.3:o:debian:debian_linux:12.0:*:*:*:*:*:*:*
fedoraproject fedora 39 cpe:2.3:o:fedoraproject:fedora:39:*:*:*:*:*:*:*

References for CVE-2023-5631

URL Tags
http://www.openwall.com/lists/oss-security/2023/11/01/1 Mailing List Third Party Advisory
http://www.openwall.com/lists/oss-security/2023/11/01/3 Mailing List Third Party Advisory
http://www.openwall.com/lists/oss-security/2023/11/17/2 Mailing List Third Party Advisory
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1054079 Mailing List Patch
https://github.com/roundcube/roundcubemail/commit/41756cc3331b495cc0b71886984474dc529dd31d Patch
https://github.com/roundcube/roundcubemail/commit/6ee6e7ae301e165e2b2cb703edf75552e5376613 Patch
https://github.com/roundcube/roundcubemail/issues/9168 Exploit Issue Tracking
https://github.com/roundcube/roundcubemail/releases/tag/1.4.15 Release Notes
https://github.com/roundcube/roundcubemail/releases/tag/1.5.5 Release Notes
https://github.com/roundcube/roundcubemail/releases/tag/1.6.4 Release Notes
https://lists.debian.org/debian-lts-announce/2023/10/msg00035.html Mailing List Third Party Advisory
https://lists.fedoraproject.org/archives/list/[email protected]/message/LK67Q46OIEGJCRQUBHKLH3IIJTBNGGX4/ Mailing List
https://roundcube.net/news/2023/10/16/security-update-1.6.4-released Release Notes
https://roundcube.net/news/2023/10/16/security-updates-1.5.5-and-1.4.15 Release Notes
https://www.debian.org/security/2023/dsa-5531 Mailing List
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-5631 US Government Resource
cvelogic Threat Intelligence