# CVE-2026-90785: Dvidelabs flatcc Struct Analysis semantics.c analyze_struct assertion

> A reachable assertion in the flatcc compiler allows remote attackers to cause a denial of service via crafted input.

- **Severity:** Medium 6.9 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 14 Sep 2026
- **Updated:** 15 Sep 2026
- **Also known as:** GHSA-q8j4-vfvg-jrfr

## What is CVE-2026-90785?

CVE-2026-90785 is a medium-severity denial of service vulnerability in Dvidelabs flatcc, published on 14 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A vulnerability was found in Dvidelabs flatcc up to 0.6.3. This affects the function analyze_struct of the file src/compiler/semantics.c of the component Struct Analysis. The manipulation results in reachable assertion. It is possible to launch the attack remotely. The exploit has been made public and could be used. The patch is identified as f705032346ee39efd7d3848c50b73d455d28d06d. A patch should be applied to remediate this issue.

Weakness: CWE-617 (Reachable Assertion)

## Which versions are affected by CVE-2026-90785?


## How do I fix CVE-2026-90785?

No fix has been published for CVE-2026-90785 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-90785 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-90785 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-90785 and fix it if it is affected.

What it is: CVE-2026-90785 is a medium-severity denial of service vulnerability in Dvidelabs flatcc, published on 14 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-90785 exists.

Affected product: Dvidelabs flatcc. 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-2026-90785/ (Markdown: https://insights.sbomify.com/CVE-2026-90785/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-90785
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-90785
- OSV: https://osv.dev/vulnerability/CVE-2026-90785

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-90785/
Summaries are generated and may contain mistakes; the official description above is the record.