In Roundcube Webmail before 1.6.17 and 1.7.x before 1.7.2, insufficient Cascading Style Sheets (CSS) sanitization in HTML e-mail messages may lead to SSRF or Information Disclosure, e.g., if stylesheet links point to local network hosts. NOTE: this issue exists because of insufficient fixes for CVE-2026-35540 and CVE-2026-48843.

The remote Debian 12 host has packages installed that are affected by multiple vulnerabilities as referenced in the dla-4823 advisory.

    -------------------------------------------------------------------------     Debian LTS Advisory DLA-4823-1                debian-lts@lists.debian.org     https://www.debian.org/lts/security/                       Guilhem Moulin     October 05, 2026                              https://wiki.debian.org/LTS
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    Package        : roundcube     Version        : 1.6.5+dfsg-1+deb12u12     CVE ID         : not yet available     Debian Bug     : 1146838

    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, email header injection,     or privilege escalation.

        Zach Hanley discovered that the CSS sanitizer was prone to declaration         smuggling via un-encoded ampersand emission, which may lead to remote         image blocking bypass or XSS.

        The CSS sanitizer is prone to property injection via body `background`         attribute, which may lead to remote image blocking bypass or XSS.

        The sendmail logic is prone to email header injection via bare CR in the         subject field, C-escape `\r` in the recipient display name, and/or         identity's organization field.

        The attachment URL is prone to TNEF MIME tag injection, which may lead         to zero-click stored XSS.

        Joshua Rogers discovered that the text/enriched part content in HTML         editor was prone to XSS.

        Joshua Rogers discovered that the contact group membership actions         add/remove were prone to cross-user access.

        The CSS sanitization fixes for CVE-2026-35540, CVE-2026-48843,         CVE-2026-62643 and CVE-2026-75006 were insufficient, allowing a         malicious embedded stylesheet in a text/html email to lead to SSRF or         information disclosure.

        Wahab Khadir discovered that insufficient HTML/CSS sanitization may lead         to remote image blocking bypass or XSS via CSS escapes in FuncIRI         attributes.

        Insufficient HTML/CSS sanitization may lead to remote image blocking         bypass or XSS via SVG SMIL src animation.

    For Debian 12 bookworm, this problem has been fixed in version     1.6.5+dfsg-1+deb12u12.

    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 11 / 12 host has packages installed that are affected by multiple vulnerabilities as referenced in the dla-4760 advisory.

    -------------------------------------------------------------------------     Debian LTS Advisory DLA-4760-1                debian-lts@lists.debian.org     https://www.debian.org/lts/security/                       Guilhem Moulin     August 29, 2026                               https://wiki.debian.org/LTS
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    Package        : roundcube     Version        : 1.4.15+dfsg.1-1+deb11u11 1.6.5+dfsg-1+deb12u11     CVE ID         : CVE-2026-74997 CVE-2026-74998 CVE-2026-74999 CVE-2026-75000                      CVE-2026-75002 CVE-2026-75003 CVE-2026-75004 CVE-2026-75006                      CVE-2026-75007 CVE-2026-75010     Debian Bug     : 1144059

    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, privilege escalation, IMAP     injection, account takeover, or remote code execution.

    CVE-2026-74997

        A remote code execution vulnerability was found in the cmd_learn learning         driver of the markasjunk plugin.  Placeholders such as %u (username), %l         (localpart) and %d (domainpart) were injected with insufficiently         sanitized/escaped values used within a `sh -c ''` shell construction,         thereby allowing remote code execution from the user used to run roundcube         (by default www-data).

        Only installations where 1/ the markasjunk plugin was enabled, and 2/         where the `$config['markasjunk_learning_driver']` setting was set to         `cmd_learn`, were affected by this vulnerability.  In particular, stock         installations were not affected since the plugin is not enabled by default.

    CVE-2026-74998

        Content proxied by the CSS proxy (which is used to retrieve remote style         sheets linked to in text/html emails) was found to be lacking basic         validation, which may result in information disclosure or XSS (cross-site         scripting) via MIME sniffing.

    CVE-2026-74999

        Paulos Yibelo discovered that the Add to address book action was subject         to stored XSS due to insufficient sanitization of error messages and         information popups.

    CVE-2026-75000

        Insufficient HTML/CSS sanitization may lead to remote image blocking bypass         or XSS via crafted SVG animate `by` attribute sent in malicious text/html         emails.

    CVE-2026-75002

        Zach Hanley discovered that mail search and RFC2088 IMAP4 LITERAL+         byte-count desynchronization may lead to IMAP command injection.

    CVE-2026-75003

        Milan Hoppe discovered that insufficient HTML/CSS sanitization may lead to         remote image blocking bypass or XSS via unclosed url() in a FuncIRI         attribute.

    CVE-2026-75004

        Milan Hoppe discovered that managesieve rule names were not sanitized,         thereby allowing arbitrary sieve injection and bypass of the         managesieve_disabled_actions restriction set by an administrator.

        This vulnerability only affects installations where the managesieve plugin         is enabled.  In particular, stock installations were not affected since the         plugin is not enabled by default.

    CVE-2026-75006

        Dmytro Ivanenko and Milan Hoppe discovered that that the CSS sanitization         fixes for CVE-2026-35540, CVE-2026-48843 and CVE-2026-62643 were         insufficient, allowing a malicious embedded stylesheet in a text/html email         to lead to SSRF or information disclosure.

    CVE-2026-75007

        Milan Hoppe discovered that the LDAP integration was subject to filter         injection via unescaped %u/%fu/%d substitution.

    CVE-2026-75010

        The modoba driver of the password plugin was found to be leaking an         authentication token, which may lead to account takeover.

        Only installations where 1/ the password plugin was enabled, and 2/         where the `$config['password_driver']` setting was set to `modoboa`,         were affected by this vulnerability.  In particular, stock installations         were not affected since the password plugin is not enabled by default.

    For Debian 11 bullseye, these problems have been fixed in version     1.4.15+dfsg.1-1+deb11u11.

    For Debian 12 bookworm, these problems have been fixed in version     1.6.5+dfsg-1+deb12u11.

    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 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
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    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, insufficient Cascading Style Sheets (CSS)     sanitization in HTML e-mail messages may lead to SSRF or Information Disclosure, e.g., if stylesheet links     point to local network hosts. NOTE: this issue exists because of insufficient fixes for CVE-2026-35540 and     CVE-2026-48843. (CVE-2026-62643)

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

ID	Name	Product	Family	Type	Severity
363011	Debian dla-4823 : roundcube - security update	Nessus	Debian Local Security Checks	Local	critical
341564	Debian dla-4760 : roundcube - security update	Nessus	Debian Local Security Checks	Local	critical
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
327051	Linux Distros Unpatched Vulnerability : CVE-2026-62643	Nessus	Misc.	Local	critical

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