PT-2026-29981 · Unknown+1 · Roundcube Webmail+1

Y0Us · Published 2026-03-18 · Updated 2026-05-07 · CVE-2026-35542

Positive Technologies (AI Summary)

CVSS v3.1

5.3

Medium

Base vector

AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Name of the Vulnerable Software and Affected Versions Roundcube Webmail versions prior to 1.5.14 and prior to 1.6.14

Description A flaw exists in Roundcube Webmail that allows bypassing the remote image blocking feature. This bypass is achieved through a crafted background attribute within the BODY element of an email message. Successful exploitation could lead to information disclosure or access-control bypass.

Recommendations Update Roundcube Webmail to version 1.5.14 or later. Update Roundcube Webmail to version 1.6.14 or later.

Fix

Weakness Enumeration

CWE-669

Related Identifiers

BDU:2026-06304

CVE-2026-35542

GHSA-5HF6-CRG4-FG59

Affected Products

Red Os

Roundcube Webmail

References · 21

• https://github.com/roundcube/roundcubemail/commit/fde14d01adc9f37893cd82b635883e516ed453f8 · Patch
• https://github.com/roundcube/roundcubemail/commit/e052328e3dc75f13adc2e314eaa4096ac21084ad · Patch
• https://github.com/roundcube/roundcubemail/commit/fd0e98178db5c73eaa93d005b561874923f9b0f0 · Patch
• https://security-tracker.debian.org/tracker/CVE-2026-35542 · Vendor Advisory
• https://osv.dev/vulnerability/GHSA-5hf6-crg4-fg59 · Vendor Advisory
• https://roundcube.net/news/2026/03/18/security-updates-1.7-rc5-1.6.14-1.5.14 · Vendor Advisory
• https://ubuntu.com/security/CVE-2026-35542 · Vendor Advisory
• https://osv.dev/vulnerability/DEBIAN-CVE-2026-35542 · Vendor Advisory
• https://bdu.fstec.ru/vul/2026-06304 · Security Note
• https://osv.dev/vulnerability/UBUNTU-CVE-2026-35542 · Vendor Advisory
• https://cve.org/CVERecord?id=CVE-2026-35542 · Security Note
• https://nvd.nist.gov/vuln/detail/CVE-2026-35542 · Security Note
• https://github.com/roundcube/roundcubemail/releases/tag/1.5.14 · Note
• https://github.com/roundcube/roundcubemail/releases/tag/1.7-rc5 · Note
• https://github.com/roundcube/roundcubemail/releases/tag/1.6.14 · Note