In Roundcube Webmail before 1.6.17 and 1.7.x before 1.7.2, there is Stored Cross-Site Scripting (XSS) via a crafted plain-text email message. The attacker-controlled JavaScript executes within the victim's authenticated session simply by opening or previewing the message (zero-click).

The remote Debian 11 / 12 host has packages installed that are affected by multiple vulnerabilities as referenced in the dla-4693 advisory.

    -------------------------------------------------------------------------     Debian LTS Advisory DLA-4693-1                debian-lts@lists.debian.org     https://www.debian.org/lts/security/                       Guilhem Moulin     July 22, 2026                                 https://wiki.debian.org/LTS
    -------------------------------------------------------------------------

    Package        : roundcube     Version        : 1.4.15+dfsg.1-1+deb11u10 1.6.5+dfsg-1+deb12u10     CVE ID         : CVE-2026-54432 CVE-2026-54433 CVE-2026-62641 CVE-2026-62642                      CVE-2026-62643 CVE-2026-62644     Debian Bug     : 1138086 1141495

    Multiple vulnerabilities were discovered in Roundcube, a skinnable AJAX     based webmail solution for IMAP servers, which could result in     cross-site scripting, server-side request forgery, information     disclosure, denial of service, or potentially account takeover.

    CVE-2026-54432

        Bohdan Kurinnoy discovered that attachment MIME types were neither         sanitized nor escaped on the attachment-validation warning page,         yielding a stored XSS vulnerability.

    CVE-2026-54433

        Bohdan Kurinnoy discovered that plain-text rendering was subject to         a zero-click stored XSS vulnerability via crafted mailto: URIs.

    CVE-2026-62641

        It was discovered that the TNEF decoder was subject to Denial of         Service via crafted compressed-RTF size in the winmail.dat         attachment file.

    CVE-2026-62642

        An infinite loop was discovered in the TNEF decoder, which may lead         to denial of service upon opening an email with a TNEF attachment.

    CVE-2026-62643

        It was discovered that the CSS sanitization fixes for CVE-2026-35540 and         CVE-2026-48843 were insufficient, allowing a malicious embedded         stylesheet in an HTML email to lead to SSRF or information         disclosure.

    CVE-2026-62644

        It was discovered that the password plugin was subject to username         spoofing via session data, which could potentially lead to account         takeover.

    For Debian 11 bullseye, these problems have been fixed in version     1.4.15+dfsg.1-1+deb11u10.

    For Debian 12 bookworm, these problems have been fixed in version     1.6.5+dfsg-1+deb12u10.

    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 LTS security advisories, how to apply     these updates to your system and frequently asked questions can be     found at: https://wiki.debian.org/LTS     Attachment:
    signature.asc     Description: PGP signature

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 remote Debian 13 host has packages installed that are affected by multiple vulnerabilities as referenced in the dsa-6391 advisory.

    - -------------------------------------------------------------------------     Debian Security Advisory DSA-6391-1                   security@debian.org     https://www.debian.org/security/                     Salvatore Bonaccorso     July 19, 2026                         https://www.debian.org/security/faq
    - -------------------------------------------------------------------------

    Package        : roundcube     CVE ID         : CVE-2026-54432 CVE-2026-54433 CVE-2026-62641 CVE-2026-62642                      CVE-2026-62643 CVE-2026-62644     Debian Bug     : 1141495

    Multiple vulnerabilities were discovered in roundcube, a skinnable AJAX     based webmail solution for IMAP servers, which could result in account     takeover, cross-site scripting, SSRF bypass, information disclosure or     denial of service.

    For the stable distribution (trixie), these problems have been fixed in     version 1.6.17+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 remote Fedora 44 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2026-517daa8d64 advisory.

    ## Release 1.7.2

    - Add HEAD request handler to the `static.php`
    - Fix so the `oauth_password_claim` claim is retrieved via token or userinfo request (#9631)
    - Fix bug where `static.php` would return a 416 error on a specific `Range` request (#10194)
    - Fix bug where configured skin logo wasn't loaded via `static.php` resulting in 404 error (#10191)
    - Fix bug where installto.sh would fail if public_html folder does not exist in the target directory     (#10202)
    - Revert Prefer 8bit over quoted-printable for HTML parts, when force_7bit is disabled (#8477) (#10198)
    - Fix incorrect unfolding of folded lines when importing vCard 2.1 contacts (#9647)
    - Fix bug where Imagick could leave large temporary files on failure (#10230)
    - Fix bug where redis/memcache session could have been updated more often than needed
    - Fix support for untyped tokens in OIDC backchannel logout, require unset `nonce` (#10097)
    - Security: Fix an infinite loop in TNEF (winmail.dat) decoder (#10193)
    - Security: Fix various vulnerabilities in the password plugin using session-injected username
    - Security: Fix stored XSS via unescaped attachment MIME type on the attachment-validation warning page     [CVE-2026-54432]
    - Security: Fix SSRF bypass via specific local address URLs - two new cases
    - Security: Fix zero-click stored XSS in plain-text rendering [CVE-2026-54433]
    - Security: Fix DoS via crafted compressed-RTF size in the TNEF (winmail.dat) file




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-c3351f4ae4 advisory.

    ## Release 1.6.17

    - Enigma: Support automatic public key lookup (import) using HKP v1 protocol (#5314)
    - Enigma: Kolab WOAT Support (#8626)
    - Security: Fix an infinite loop in TNEF (winmail.dat) decoder (#10193)
    - Security: Fix various vulnerabilities in the password plugin using session-injected username
    - Security: Fix stored XSS via unescaped attachment MIME type on the attachment-validation warning page     [CVE-2026-54432]
    - Security: Fix SSRF bypass via specific local address URLs - two new cases
    - Security: Fix zero-click stored XSS in plain-text rendering [CVE-2026-54433]
    - Security: Fix DoS via crafted compressed-RTF size in the TNEF (winmail.dat) file



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

  - In Roundcube Webmail before 1.6.17 and 1.7.x before 1.7.2, there is Stored Cross-Site Scripting (XSS) via     a crafted plain-text email message. The attacker-controlled JavaScript executes within the victim's     authenticated session simply by opening or previewing the message (zero-click). (CVE-2026-54433)

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

The version of FreeBSD installed on the remote host is prior to tested version. It is, therefore, affected by multiple vulnerabilities as referenced in the d5578ba4-7889-11f1-b72c-8447094a420f advisory.

    The Rouncube project reports:
    See links for more detail

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

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

ID	Name	Product	Family	Type	Severity
328879	Debian dla-4693 : roundcube - security update	Nessus	Debian Local Security Checks	Local	critical
327907	Debian dsa-6391 : roundcube - security update	Nessus	Debian Local Security Checks	Local	critical
327217	Fedora 44 : roundcubemail (2026-517daa8d64)	Nessus	Fedora Local Security Checks	Local	critical
327216	Fedora 43 : roundcubemail (2026-c3351f4ae4)	Nessus	Fedora Local Security Checks	Local	critical
325353	Linux Distros Unpatched Vulnerability : CVE-2026-54433	Nessus	Misc.	Local	critical
325259	FreeBSD : Roundcube -- Multiple vulnerabilities (d5578ba4-7889-11f1-b72c-8447094a420f)	Nessus	FreeBSD Local Security Checks	Local	critical

Detections

Analytics

CVE-2026-54433

critical

Tenable Plugins

critical

critical

critical

critical

critical

critical