An issue was discovered in Roundcube Webmail before 1.5.14 and 1.6.14. XSS exists because of insufficient HTML attachment sanitization in preview mode. A victim must preview a text/html attachment.

The remote Fedora 42 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2026-051825ca18 advisory.

    **Version 1.6.15**

    This is a security update to the stable version 1.6 of Roundcube Webmail.
    It provides fixes to some regressions introduced in the previous release as well a recently reported     security vulnerability:

    -    SVG Animate FUNCIRI Attribute Bypass  Remote Image Loading via fill/filter/stroke, reported by     class_nzm.

    This version is considered stable and we recommend to update all productive installations of Roundcube     1.6.x with it. Please do backup your data before updating!

    CHANGELOG

    -    Fix regression where mail search would fail on non-ascii search criteria (#10121)
    -    Fix regression where some data url images could get ignored/lost (#10128)
    -    Fix SVG Animate FUNCIRI Attribute Bypass  Remote Image Loading via fill/filter/stroke



Tenable has extracted the preceding description block directly from the Fedora security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote Fedora 43 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2026-8ba1a085a9 advisory.

    **Version 1.6.15**

    This is a security update to the stable version 1.6 of Roundcube Webmail.
    It provides fixes to some regressions introduced in the previous release as well a recently reported     security vulnerability:

    -    SVG Animate FUNCIRI Attribute Bypass  Remote Image Loading via fill/filter/stroke, reported by     class_nzm.

    This version is considered stable and we recommend to update all productive installations of Roundcube     1.6.x with it. Please do backup your data before updating!

    CHANGELOG

    -    Fix regression where mail search would fail on non-ascii search criteria (#10121)
    -    Fix regression where some data url images could get ignored/lost (#10128)
    -    Fix SVG Animate FUNCIRI Attribute Bypass  Remote Image Loading via fill/filter/stroke



Tenable has extracted the preceding description block directly from the Fedora security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote Debian 13 host has packages installed that are affected by multiple vulnerabilities as referenced in the dsa-6196 advisory.

    - -------------------------------------------------------------------------     Debian Security Advisory DSA-6196-1                   security@debian.org     https://www.debian.org/security/                     Salvatore Bonaccorso     April 04, 2026                        https://www.debian.org/security/faq
    - -------------------------------------------------------------------------

    Package        : roundcube     CVE ID         : CVE-2026-35537 CVE-2026-35538 CVE-2026-35539 CVE-2026-35540                      CVE-2026-35541 CVE-2026-35542 CVE-2026-35543 CVE-2026-35544                      CVE-2026-35545     Debian Bug     : 1131182 1132268

    Multiple vulnerabilities were discovered in roundcube, a skinnable AJAX     based webmail solution for IMAP servers, which could result in     information disclosure, IMAP injection, CSRF bypass, bypass of remote     image blocking, cross-site scripting, access control bypass, or     privilege escalation.

    For the oldstable distribution (bookworm), these problems have been fixed     in version 1.6.5+dfsg-1+deb12u8.

    For the stable distribution (trixie), these problems have been fixed in     version 1.6.15+dfsg-0+deb13u1.

    We recommend that you upgrade your roundcube packages.

    For the detailed security status of roundcube please refer to its     security tracker page at:
    https://security-tracker.debian.org/tracker/roundcube

    Further information about Debian Security Advisories, how to apply     these updates to your system and frequently asked questions can be     found at: https://www.debian.org/security/

    Mailing list: debian-security-announce@lists.debian.org

Tenable has extracted the preceding description block directly from the Debian security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - An issue was discovered in Roundcube Webmail before 1.5.14 and 1.6.14. XSS exists because of insufficient     HTML attachment sanitization in preview mode. A victim must preview a text/html attachment.
    (CVE-2026-35539)

Note that Nessus relies on the presence of the package as reported by the vendor.

ID	Name	Product	Family	Severity
305675	Fedora 42 : roundcubemail (2026-051825ca18)	Nessus	Fedora Local Security Checks	high
305671	Fedora 43 : roundcubemail (2026-8ba1a085a9)	Nessus	Fedora Local Security Checks	high
305020	Debian dsa-6196 : roundcube - security update	Nessus	Debian Local Security Checks	high
304892	Linux Distros Unpatched Vulnerability : CVE-2026-35539	Nessus	Misc.	medium

Detections

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CVE-2026-35539

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Tenable Plugins

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