---
id: CVE-2026-88896
title: EspoCRM before 10.0.4 is vulnerable to server-side request forgery
summary: >-
  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 doe…
severity: medium
cvss: 5.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N'
cwe:
  - CWE-918
vendor: espocrm
product: espocrm
affected:
  - espocrm < 10.0.4
published: '2026-09-10'
updated: '2026-09-15'
sourceUpdated: '2026-09-15T15:17:26.330'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-88896'
references:
  - url: 'https://github.com/espocrm/espocrm/security/advisories/GHSA-xwmh-j8hf-cfqw'
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/espocrm-before-10.0.4-ssrf-via-ipv6-transition-address-bypass
    label: disclosure@vulncheck.com
tags:
  - nvd
  - cve.org
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-09-15T14:29:07.490725Z'
epss: 0.00371
epssPercentile: 0.28292
ingestedAt: '2026-09-10T13:50:37.333Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.