Security Vulnerabilities
webpack-dev-server is a development server that provides live reloading for webpack projects. In versions before 5.2.7 and in version 6.0.0, when a proxy entry is configured to forward WebSockets, the server forwards non-HMR WebSocket upgrade requests to the proxy target without validating the Host or Origin headers, so the allowedHosts protection does not apply to those proxied upgrades. A malicious web page visited by a developer can open a cross-origin WebSocket through the dev server and read from and write to the proxied backend, even when the server is bound to loopback. The issue is fixed in webpack-dev-server 5.2.7 and 6.1.0, where proxied WebSocket upgrades pass the same Host and Origin validation as the HMR WebSocket, and users should upgrade to one of those versions or later. As a workaround, omit WebSocket forwarding from proxy entries that do not need it and scope the proxy to specific paths.
CVSS Score
8.2
EPSS Score
0.001
Published
2026-10-22
webpack-dev-server is a development server that provides live reloading for webpack projects. In versions from 5.1.0 before 5.2.7 and in version 6.0.0, the unauthenticated open-editor endpoint validates the Host header with a regular expression meant for browser Origin schemes, so a Host value beginning with file: or with an extension scheme short-circuits the hostname and allowedHosts checks. A network peer that can reach the dev server can send a request with a malformed Host that passes validation and then causes the endpoint's URL construction to throw, and in the default non-production mode the server returns an HTTP 500 body containing the full exception stack trace, which discloses absolute filesystem paths, installed module locations, and internal source line numbers. The server keeps running, so there is no denial of service. The issue is fixed in webpack-dev-server 5.2.7 and 6.1.0, and users should upgrade to one of those versions or later.
CVSS Score
5.3
EPSS Score
0.003
Published
2026-10-22
Roundcube Webmail before 1.6.20 and 1.7.x before 1.7.5 is affected by a remote content blocking bypass. rcube_washtml inspected the SVG SMIL animation attributes `to`, `from` and values for URIs, but not `by`; so markup such as in an HTML message caused remote content to be loaded without the user's consent, disclosing the client IP address and confirming that the message was opened. Upstream fixed this in the commit “Fix remote-content blocker bypass via SVG SMIL `by` attribute”.
CVSS Score
5.3
EPSS Score
0.004
Published
2026-10-22
Roundcube Webmail 1.6.14 before 1.6.20 and 1.7.0 before 1.7.5 is affected by a server-side request forgery filter bypass. The network blocklist used by rcube_utils::is_local_url() omitted the RFC 6052 NAT64 prefix 64:ff9b::/96, the RFC 8215 local-use NAT64 prefix 64:ff9b:1::/48 and the unspecified address ::/128, so URLs such as http://[64:ff9b::7f00:1]/ passed the filter and reached loopback, link-local and cloud metadata addresses. Upstream fixed this in the commit “Fix SSRF filter (is_local_url()) bypass via NAT64 64:ff9b::/96”.
CVSS Score
7.2
EPSS Score
0.004
Published
2026-10-22
Roundcube Webmail before 1.6.20 and 1.7.x before 1.7.5 is affected by an uncontrolled resource consumption vulnerability in the CSS proxy (the utils/modcss action). The fetched stylesheet was read into memory in full, with no size limit and no read timeout, so a stylesheet URL referencing an attacker-controlled host could be used to exhaust server memory. Upstream fixed this in the commit “Add a size limit to the CSS proxy content processing”, which caps the response at 5 MB, reads it as a stream and applies a read timeout.
CVSS Score
5.3
EPSS Score
0.004
Published
2026-10-22
Roundcube Webmail before 1.6.20 and 1.7.x before 1.7.5 is affected by an improper authentication vulnerability in multi-host installations. When a user logs in with an alias address, rcube_user::query() matched the address against identity records without qualifying the lookup by IMAP host, so a login could be resolved to a user account belonging to a different IMAP host. Upstream fixed this in the commit “Fix bug where an alias login wasn’t qualified by IMAP host”.
CVSS Score
6.8
EPSS Score
0.004
Published
2026-10-22
Roundcube Webmail before 1.6.20 and 1.7.x before 1.7.5 is affected by a CSS scoping bypass in HTML messages. rcube_utils::mod_css_styles() did not treat an at-rule prologue such as @layer a; as a selector boundary, and did not handle selectors beginning with ::, so selectors following an at-rule were left unscoped and applied to the whole Roundcube interface instead of being confined to the message body. This allows an HTML message to restyle application chrome for UI redressing and spoofing. Upstream fixed this in the commit “Fix CSS scoping bypass in HTML messages using at-rules”.
CVSS Score
6.5
EPSS Score
0.003
Published
2026-10-22
Roundcube Webmail before 1.6.20 and 1.7.x before 1.7.5 allows the ImageMagick resource limits to be bypassed during thumbnail generation. When rcube_image falls back to GD, the available-memory check was applied only on Windows, so on other platforms a crafted image with large dimensions was processed by GD without any resource limit and could exhaust server memory. Upstream fixed this in the commit “Fix ImageMagick resource limits bypass by GD fallback during thumbnail generation”, which applies the memory check on all platforms.
CVSS Score
3.7
EPSS Score
0.005
Published
2026-10-22
Roundcube Webmail before 1.6.20 and 1.7.x before 1.7.5 contains an object injection primitive in rcube_session::unserialize(). A session key prefixed with “!” was treated as having no value, and the reconstructed serialized string was emitted with a key but no corresponding value, desynchronizing the remainder of the input so that following session data was interpreted as a serialized value. This yields a PHP object injection primitive for an attacker able to influence stored session data. Upstream fixed this in the commit “Fix object injection primitive in rcube_session::unserialize() via “!”-prefixed session keys”, which rejects such keys.
CVSS Score
7.4
EPSS Score
0.004
Published
2026-10-22
Roundcube Webmail before 1.6.20 and 1.7.x before 1.7.5 is affected by a mail header injection vulnerability. rcmail_sendmail stripped newline characters only from the Subject and Organization headers, leaving other header values taken from request parameters unsanitized, so a remote authenticated attacker could inject arbitrary headers into an outgoing message via the References, In-Reply-To, Message-ID and From parameters. Upstream fixed this in the commit “Fix mail header injection via References/In-Reply-To/Message-ID/From parameters”, which normalizes whitespace in every string header value.
CVSS Score
5.0
EPSS Score
0.003
Published
2026-10-22