An issue was discovered in Roundcube Webmail before 1.5.14 and 1.6.14. Unsafe deserialization in the redis/memcache session handler may lead to arbitrary file write operations by unauthenticated attackers via crafted session data.

The remote openSUSE 16 host has a package installed that is affected by a vulnerability as referenced in the openSUSE- SU-2026:20586-1 advisory.

    Changes in roundcubemail:

    - update to 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!

      - 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 (bsc#1261157)

    - update to 1.6.14       This is a security update to the stable version 1.6 of Roundcube Webmail.
      - Fix Postgres connection using IPv6 address (#10104)
      - Security: Fix pre-auth arbitrary file write via unsafe deserialization in redis/memcache session     handler         (bsc#1261488, CVE-2026-35537)
      - Security: Fix bug where a password could get changed without providing the old password
      - Security: Fix IMAP Injection + CSRF bypass in mail search
      - Security: Fix remote image blocking bypass via various SVG animate attributes
      - Security: Fix remote image blocking bypass via a crafted body background attribute
      - Security: Fix fixed position mitigation bypass via use of !important
      - Security: Fix XSS issue in a HTML attachment preview
      - Security: Fix SSRF + Information Disclosure via stylesheet links to a local network hosts

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

Note that Nessus has not tested for this issue 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. Unsafe deserialization in the     redis/memcache session handler may lead to arbitrary file write operations by unauthenticated attackers     via crafted session data. (CVE-2026-35537)

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

There are packages installed that are affected by a vulnerability referenced in the following CVE:

  - An issue was discovered in Roundcube Webmail before 1.5.14 and 1.6.14. Unsafe deserialization in the
    redis/memcache session handler may lead to arbitrary file write operations by unauthenticated attackers
    via crafted session data. (CVE-2026-35537)

ID	Name	Product	Family	Type	Severity
309156	openSUSE 16 Security Update : roundcubemail (openSUSE-SU-2026:20586-1)	Nessus	SuSE Local Security Checks	Local	high
305020	Debian dsa-6196 : roundcube - security update	Nessus	Debian Local Security Checks	Local	high
304896	Linux Distros Unpatched Vulnerability : CVE-2026-35537	Nessus	Misc.	Local	high
439862	SCA: security update for roundcube/roundcubemail (GHSA-rxj3-rrwm-pj4r)	Tenable Cloud Security	SCA Checks	Local	high
439862	SCA: security update for roundcube/roundcubemail (GHSA-rxj3-rrwm-pj4r)	Tenable Self-Hosted Container Security	SCA Checks	Local	high

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CVE-2026-35537

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