23 Oct 2026 15:48:27 UTC
EspoCRM before 10.0.4 SSRF via IPv6 Transition Address Bypass
cve-program · CVE-2026-88896 · Published
CVE-2026-88896
EspoCRM before 10.0.4 SSRF via IPv6 Transition Address Bypass
CVSS 4.0 6.9 MEDIUMCVSS 3.1 5.3 MEDIUMCheck source for fixed versionsKEV status unknown
cve-program · CVE-2026-88896
PublishedEspoCRM 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.
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