{"id":"CVE-2026-88896","summary":"EspoCRM before 10.0.4 SSRF via IPv6 Transition Address Bypass","details":"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.","aliases":["GHSA-xwmh-j8hf-cfqw"],"modified":"2026-09-12T03:47:22.553596119Z","published":"2026-09-10T13:05:43.054Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/88xxx/CVE-2026-88896.json","cna_assigner":"VulnCheck","cwe_ids":["CWE-918"]},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/88xxx/CVE-2026-88896.json"},{"type":"ADVISORY","url":"https://github.com/espocrm/espocrm/security/advisories/GHSA-xwmh-j8hf-cfqw"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-88896"},{"type":"ADVISORY","url":"https://www.vulncheck.com/advisories/espocrm-before-10.0.4-ssrf-via-ipv6-transition-address-bypass"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/espocrm/espocrm","events":[{"introduced":"0"},{"fixed":"0a50f3a37c8e2d96c0746a07ff698c9ef1c0c3aa"}],"database_specific":{"extracted_events":[{"introduced":"0"},{"fixed":"10.0.4"}],"source":["AFFECTED_FIELD","DESCRIPTION"]}}],"versions":["10.0.3","10.0.2","10.0.1","10.0.0","9.3.0","9.2.0","9.1.0","9.0.2","9.0.1","9.0.0","8.4.0","8.2.0","8.1.0","8.0.2","8.0.1","8.0.0","7.4.3","7.4.2","7.4.1","7.4.0","7.3.0","7.2.0","7.1.3","7.1.2","7.1.1","7.1.0","7.0.8","7.0.7","7.0.6","7.0.5","7.0.4","7.0.3","7.0.2","7.0.1","7.0.0","6.0.1","6.0.0","6.0.0-beta4","6.0.0-beta2","6.0.0-beta1","5.9.2","5.9.1","5.9.0","5.8.2","5.8.1","5.8.0","5.7.5","5.7.4","5.7.3","5.7.2","5.7.1","5.7.0","5.6.1","5.6.0","5.5.1","5.5.0","5.4.3","5.4.2","5.4.1","5.4.0","5.3.2","5.3.1","5.3.0","5.2.5","5.2.4","5.2.3","5.2.2","5.2.1","5.2.0","5.1.2","5.1.1","5.1.0","5.0.1","5.0.0","4.8.0","4.7.0","4.6.0","4.5.0","4.4.0","4.3.0","4.3.0-beta.2","4.3.0-beta.1","4.2.4","4.2.3","4.2.2","4.2.1","4.2.0","4.1.4","4.1.3","4.1.2","4.1.1","4.1.0","4.0.3","4.0.2","4.0.1","4.0.0","4.0.0-beta.4","4.0.0-beta.3","4.0.0-beta.2","4.0.0-beta.1","3.9.1","3.9.0","3.8.0","3.7.1","3.7.0","3.6.1","3.6.0","3.5.0","3.4.2","3.4.1","3.4.0","3.3.0","3.2.0","3.1.0","3.0.0","2.9.0","2.8.1","2.8.0","2.6.0","2.5.2","2.5.1","2.5.0","2.4.0","2.3.0","2.0.1","1.2.0","1.1.2","1.1.1","1.1.0","1.0.1","1.0.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-88896.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:L/SI:L/SA:L"}]}