# CVE-2026-3404: thinkgem JeeSite Endpoint CasOutHandler.java xml external entity reference

> Remote attackers can exploit an XML External Entity vulnerability in JeeSite's CasOutHandler to read sensitive data or cause denial of service.

- **Severity:** Low 2.3 (`CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 2 Mar 2026
- **Updated:** 2 Mar 2026
- **Also known as:** GHSA-7p6h-h74m-fpv3

## What is CVE-2026-3404?

CVE-2026-3404 is a low-severity vulnerability in thinkgem JeeSite, published on 2 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A flaw has been found in thinkgem JeeSite up to 5.15.1. Impacted is an unknown function of the file /com/jeesite/common/shiro/cas/CasOutHandler.java of the component Endpoint. Executing a manipulation can lead to xml external entity reference. The attack may be performed from remote. Attacks of this nature are highly complex. The exploitability is considered difficult. The exploit has been published and may be used. The vendor was contacted early about this disclosure but did not respond in any way.

Weakness: CWE-611 (Improper Restriction of XML External Entity Reference), CWE-610 (Externally Controlled Reference to a Resource in Another Sphere)

## Which versions are affected by CVE-2026-3404?

It affects 1 product.


Products: Jeesite Jeesite.

## How do I fix CVE-2026-3404?

No fix has been published for CVE-2026-3404 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-3404 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-3404 exists.

## Other vulnerabilities in thinkgem JeeSite

- [CVE-2023-34601](https://insights.sbomify.com/CVE-2023-34601/): SQL injection in n/a (critical 9.8)
- [CVE-2020-19229](https://insights.sbomify.com/CVE-2020-19229/): Deserialization in n/a (critical 9.8)
- [CVE-2024-8112](https://insights.sbomify.com/CVE-2024-8112/): thinkgem JeeSite Cookie login cross site scripting (medium 6.9)
- [CVE-2019-1010201](https://insights.sbomify.com/CVE-2019-1010201/): SQL injection in Jeesite (medium 6.5)
- [CVE-2019-1010202](https://insights.sbomify.com/CVE-2019-1010202/): XML external entity in Jeesite (medium 6.5)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-3404 and fix it if it is affected.

What it is: CVE-2026-3404 is a low-severity vulnerability in thinkgem JeeSite, published on 2 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-3404 exists.

Affected product: thinkgem JeeSite. 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-2026-3404/ (Markdown: https://insights.sbomify.com/CVE-2026-3404/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-3404
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-3404
- OSV: https://osv.dev/vulnerability/CVE-2026-3404

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-3404/
Summaries are generated and may contain mistakes; the official description above is the record.