# CVE-2026-12606: Other in Eclipse GlassFish

> Attackers can perform HTTP request smuggling via malformed trailer headers in Eclipse Grizzly, requiring strict validation settings or an upgrade.

- **Severity:** Medium 6.3 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 14 Jul 2026
- **Updated:** 27 Jul 2026
- **Also known as:** GHSA-c269-4hpf-qfhc, UBUNTU-CVE-2026-12606

## What is CVE-2026-12606?

CVE-2026-12606 is a medium-severity vulnerability in Eclipse GlassFish, published on 14 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Eclipse Grizzly in versions before 5.0.2, cannot properly parse the trailer section in malformed trailer header's line, which can be leveraged to perform HTTP request smuggling. Grizzly 5.0.1 supports system properties that enable the behavior that fixes the vulnerability - set org.glassfish.grizzly.http.STRICT_HEADER_NAME_VALIDATION_RFC_9110 and org.glassfish.grizzly.http.STRICT_HEADER_VALUE_VALIDATION_RFC_9110 system properties to "true".

Weakness: CWE-444 (Inconsistent Interpretation of HTTP Requests)

## Which versions are affected by CVE-2026-12606?

It affects 1 product.


Products: Eclipse Grizzly.

## How do I fix CVE-2026-12606?

No fix has been published for CVE-2026-12606 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-12606 being exploited?

There is no known exploitation of CVE-2026-12606 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-12606 and fix it if it is affected.

What it is: CVE-2026-12606 is a medium-severity vulnerability in Eclipse GlassFish, published on 14 Jul 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-2026-12606 in the wild and no public exploit code.

Affected product: Eclipse GlassFish. 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-2026-12606/ (Markdown: https://insights.sbomify.com/CVE-2026-12606/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-12606
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-12606
- OSV: https://osv.dev/vulnerability/CVE-2026-12606

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-12606/
Summaries are generated and may contain mistakes; the official description above is the record.