CVE-2026-35544

MEDIUMNVD 5.35.3—

5.3

An issue was discovered in Roundcube Webmail before 1.5.14 and 1.6.14. Insufficient Cascading Style Sheets (CSS) sanitization in HTML e-mail messages may lead to a fixed-position mitigation bypass via the use of !important.

CVSS v3: 5.3
EG Score: 5.3(medium)
EPSS: 3.2%
KEV: Not listed

Published

April 3, 2026

Last Modified

April 9, 2026

References (7)

Affected Packages

(1 across 1 ecosystem)

Packagist(1)

Package	Vulnerable range	Fixed in	Dependents
roundcube/roundcubemail	1.7-beta ... 1.7-rc4 (6 versions)	1.7-rc5	—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

CWE-669Incorrect Resource Transfer Between Spheres

Data Freshness Timeline

(refreshed 16× in last 7d / 20× in last 30d)

Every time one of our enrichment pipelines (NVD, MITRE cvelistV5, EPSS, CISA KEV, GHSA, OSV, vendor advisories) ran against this CVE. Most recent first.

2026-05-31 22:30 UTCepss_batch
2026-05-31 22:30 UTCepss_batch
2026-05-31 00:16 UTCepss_batch
2026-05-31 00:16 UTCepss_batch
2026-05-31 00:16 UTCepss_batch
2026-05-29 13:44 UTCepss_batch
2026-05-29 13:44 UTCepss_batch
2026-05-28 13:44 UTCepss_batch
2026-05-28 13:44 UTCepss_batch
2026-05-28 13:44 UTCepss_batch
2026-05-27 13:40 UTCepss_batch
2026-05-27 13:40 UTCepss_batch
2026-05-27 13:40 UTCepss_batch
2026-05-26 13:44 UTCepss_batch
2026-05-26 07:18 UTCepss_batch
2026-05-26 07:18 UTCepss_batch
2026-05-23 00:08 UTCEG score recompute
2026-05-20 22:38 UTCepss_batch
2026-05-20 22:38 UTCepss_batch
2026-05-20 19:18 UTCEG score recompute

Frequently asked(5)

What is CVE-2026-35544?

CVE-2026-35544 is a medium vulnerability published on April 3, 2026. An issue was discovered in Roundcube Webmail before 1.5.14 and 1.6.14. Insufficient Cascading Style Sheets (CSS) sanitization in HTML e-mail messages may lead to a fixed-position mitigation bypass via the use of !important.

When was CVE-2026-35544 disclosed?

CVE-2026-35544 was first published in the National Vulnerability Database on April 3, 2026, with the most recent update on April 9, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.

Is CVE-2026-35544 actively exploited?

CVE-2026-35544 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 3.2% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.

What is the CVSS score of CVE-2026-35544?

CVE-2026-35544 has a CVSS v3 base score of 5.3 (NVD).

How do I remediate CVE-2026-35544?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-35544, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-35544

Explore →

Is Your Infrastructure Affected by CVE-2026-35544?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Start Free Scan →Browse All CVEs