EspoCRM up to 10.0.3 Host Validation /Attachment/fromImageUrl ipAddressIsNotInternal server-side request forgery

Summaryinfo

A vulnerability marked as critical has been reported in EspoCRM up to 10.0.3. Impacted is the function HostCheck::ipAddressIsNotInternal of the file /Attachment/fromImageUrl of the component Host Validation. The manipulation leads to server-side request forgery. This vulnerability is uniquely identified as CVE-2026-88896. The attack is possible to be carried out remotely. No exploit exists. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, has been found in EspoCRM up to 10.0.3. This issue affects the function HostCheck::ipAddressIsNotInternal of the file /Attachment/fromImageUrl of the component Host Validation. The manipulation with an unknown input leads to a server-side request forgery vulnerability. Using CWE to declare the problem leads to CWE-918. The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

EspoCRM before 10.0.4 is vulnerable to server-side request forgery. HostCheck::ipAddressIsNotInternal(), which validates outbound URLs to block requests to internal/private IP addresses, strips ::ffff: (IPv4-mapped IPv6) prefixes but does not recognize IPv6 transition addresses that embed private IPv4 addresses: NAT64 (64:ff9b::), 6to4 (2002::), and Teredo (2001:0000::). An attacker who controls a domain with AAAA records pointing to such transition addresses can bypass both the internal-host validation and the CURLOPT_RESOLVE IP-pinning check, causing EspoCRM to issue outbound requests to internal network services. Affected paths include POST /Attachment/fromImageUrl, reachable by any authenticated user with attachment access, and outbound webhook delivery, which requires an admin or API user.

The advisory is shared at github.com. The identification of this vulnerability is CVE-2026-88896 since 09/10/2026. The exploitation is known to be easy. The attack may be initiated remotely. Technical details are known, but no exploit is available.

Upgrading to version 10.0.4 eliminates this vulnerability.

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Productinfo

Name

• EspoCRM

Version

• 10.0.0
• 10.0.1
• 10.0.2
• 10.0.3

License

• open-source

Website

• Product: https://github.com/espocrm/espocrm/

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