CVE-2021-26925

Roundcube before 1.4.11 allows XSS via crafted Cascading Style Sheets (CSS) token sequences...

5.4 MediumFix available

Roundcube before 1.4.11 allows XSS via crafted Cascading Style Sheets (CSS) token sequences during HTML email rendering.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: Low
User interaction: Required

What an attacker can affect

Confidentiality: Low
Integrity: Low
Availability: None

Exploit likelihood

1.02%Unchanged since Apr 14, 2021

What each source reports

NVD Score used 5.4

Roundcube before 1.4.11 allows XSS via crafted Cascading Style Sheets (CSS) token sequences during HTML email rendering.

Record: CVE-2021-26925
CVSS 3.1: 5.4 MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
CVSS 2.0: 3.5 LowAV:N/AC:M/Au:S/C:N/I:P/A:N
Weakness: CWE-79
Updated: 2026-11-02

CVE List No score

Roundcube before 1.4.11 allows XSS via crafted Cascading Style Sheets (CSS) token sequences during HTML email rendering.

Record: CVE-2021-26925
Updated: 2026-11-02

EUVDEUVD-2021-13707 No score

Roundcube before 1.4.11 allows XSS via crafted Cascading Style Sheets (CSS) token sequences during HTML email rendering.

Record: EUVD-2021-13707
Updated: 2026-11-03

GitHub AdvisoriesGHSA-xw9h-8vfr-ppf5 5.4

Roundcube before 1.4.11 allows XSS via crafted Cascading Style Sheets (CSS) token sequences...

Roundcube before 1.4.11 allows XSS via crafted Cascading Style Sheets (CSS) token sequences during HTML email rendering.

Record: GHSA-xw9h-8vfr-ppf5
CVSS 3.1: 5.4 MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
Weakness: CWE-79
Updated: 2026-11-02

OSV 5.4

Roundcube before 1.4.11 allows XSS via crafted Cascading Style Sheets (CSS) token sequences during HTML email rendering.

Record: CVE-2021-26925
CVSS 3.1: 5.4 MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
Updated: 2026-11-02

OSVDEBIAN-CVE-2021-26925 5.4

Roundcube before 1.4.11 allows XSS via crafted Cascading Style Sheets (CSS) token sequences during HTML email rendering.

Record: DEBIAN-CVE-2021-26925
CVSS 3.1: 5.4 MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
Updated: 2026-11-02

OSVUBUNTU-CVE-2021-26925 5.4

Roundcube before 1.4.11 allows XSS via crafted Cascading Style Sheets (CSS) token sequences during HTML email rendering.

Record: UBUNTU-CVE-2021-26925
CVSS 3.1: 5.4 MediumCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
Updated: 2026-11-02

OSVBIT-roundcube-2021-26925 No score

Roundcube before 1.4.11 allows XSS via crafted Cascading Style Sheets (CSS) token sequences during HTML email rendering.

Record: BIT-roundcube-2021-26925
Updated: 2026-11-02

OSVMGASA-2021-0130 No score

Updated roundcubemail package fixes security vulnerability

This update fixes cross-site scripting (XSS) via HTML messages with malicious CSS content (CVE-2021-26925).

Record: MGASA-2021-0130
Updated: 2026-11-02

Affected products

Affected packages

Affected packages
Package	Affected	Fixed
`roundcube` Bitnami	before 1.4.11	1.4.11
`roundcube` Debian:12	before 1.4.11+dfsg.1-1	1.4.11+dfsg.1-1
`roundcube` Debian:13	before 1.4.11+dfsg.1-1	1.4.11+dfsg.1-1
`roundcube` Debian:14	before 1.4.11+dfsg.1-1	1.4.11+dfsg.1-1
`roundcubemail` Mageia:7	before 1.4.11-1.mga7	1.4.11-1.mga7
`roundcube` Ubuntu:22.04:LTS	before 1.5.0+dfsg.1-2, plus listed versions 1.4.11+dfsg.1-4	1.5.0+dfsg.1-2

History

History
Recorded	Changed	Sources
Nov 3, 2026	aliases	EUVD
Nov 2, 2026	first indexed	CVE List, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2021-26925 is a medium vulnerability (CVSS 5.4) in Fedoraproject Fedora, published February 9, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.02%, the 63rd percentile. Fixed in roundcube 1.4.11.

References

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