# CVE-2026-90622: GNU libredwg Layer Encoding dwg.spec DWG_TABLE null pointer dereference

> A local attacker can cause a denial of service via null pointer dereference in GNU libredwg's layer encoding by manipulating a DWG file.

- **Severity:** Medium 4.8 (`CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 14 Sep 2026
- **Updated:** 15 Sep 2026
- **Also known as:** GHSA-4mr5-prf2-3x3c

## What is CVE-2026-90622?

CVE-2026-90622 is a medium-severity vulnerability in GNU libredwg, published on 14 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

A security flaw has been discovered in GNU libredwg 0.13.4. This impacts the function DWG_TABLE of the file src/dwg.spec of the component Layer Encoding. Performing a manipulation results in null pointer dereference. The attack needs to be approached locally. The exploit has been released to the public and may be used for attacks. Upgrading to version 0.14 will fix this issue. The patch is named f5b548c4c1697d66c3dabd0f6a49280a14365a3a. The affected component should be upgraded. The FIELD_HANDLE macro itself is NULL-safe (emits null_handle) - only the two raw zeroing assignments added by 27118c40 ("encode: also disable LAYER.material") dereferenced a NULL material handle; the fix restores the file's existing if (_obj->style) guard convention for material.

Weakness: CWE-476 (NULL Pointer Dereference), CWE-404 (Improper Resource Shutdown or Release)

## Which versions are affected by CVE-2026-90622?


## How do I fix CVE-2026-90622?

No fix has been published for CVE-2026-90622 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-90622 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-90622 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-90622 and fix it if it is affected.

What it is: CVE-2026-90622 is a medium-severity vulnerability in GNU libredwg, published on 14 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-90622 exists.

Affected product: GNU libredwg. 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-2026-90622/ (Markdown: https://insights.sbomify.com/CVE-2026-90622/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-90622
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-90622
- OSV: https://osv.dev/vulnerability/CVE-2026-90622

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-90622/
Summaries are generated and may contain mistakes; the official description above is the record.