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

> Authenticated attackers can bypass IP validation using IPv6 transition addresses to force EspoCRM to make requests to internal network services.

- **Severity:** Medium 6.9 (`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`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 10 Sep 2026
- **Updated:** 15 Sep 2026
- **Also known as:** GHSA-p98c-469w-949w, GHSA-xwmh-j8hf-cfqw

## What is CVE-2026-88896?

CVE-2026-88896 is a medium-severity server-side request forgery vulnerability in espocrm, published on 10 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official 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.

Weakness: CWE-918 (Server-Side Request Forgery)

## Which versions are affected by CVE-2026-88896?


## How do I fix CVE-2026-88896?

No fix has been published for CVE-2026-88896 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-88896 being exploited?

There is no known exploitation of CVE-2026-88896 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-88896 and fix it if it is affected.

What it is: CVE-2026-88896 is a medium-severity server-side request forgery vulnerability in espocrm, published on 10 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-88896 in the wild and no public exploit code.

Affected product: espocrm. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-88896/ (Markdown: https://insights.sbomify.com/CVE-2026-88896/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-88896
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-88896
- OSV: https://osv.dev/vulnerability/CVE-2026-88896

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-88896/
Summaries are generated and may contain mistakes; the official description above is the record.