# CVE-2026-90978: Filter Gallery < 1.1.5 - Subscriber+ Arbitrary Post Overwrite and Plugin Option Deletion via Fail-Open Nonce Check

> Low-privileged users can overwrite arbitrary posts and delete plugin options due to missing nonce and capability checks in AJAX handlers.

- **Severity:** High 7.1 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L`)
- **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:** 18 Sep 2026
- **Updated:** 18 Sep 2026
- **Also known as:** GHSA-hrf4-x4j2-f44x

## What is CVE-2026-90978?

CVE-2026-90978 is a high-severity missing authorization vulnerability in Unknown Filter Gallery, published on 18 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

The Filter Gallery WordPress plugin before 1.1.5 does not verify the nonce on several of its AJAX handlers when the nonce field is omitted, and applies no capability check, allowing low-privileged users to overwrite the content of arbitrary posts and delete the Filter Gallery WordPress plugin before 1.1.5's stored gallery options.

Weakness: CWE-284 (Improper Access Control)

## Which versions are affected by CVE-2026-90978?


## How do I fix CVE-2026-90978?

No fix has been published for CVE-2026-90978 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-90978 being exploited?

There is no known exploitation of CVE-2026-90978 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-90978 and fix it if it is affected.

What it is: CVE-2026-90978 is a high-severity missing authorization vulnerability in Unknown Filter Gallery, published on 18 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-90978 in the wild and no public exploit code.

Affected product: Unknown Filter Gallery. 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-2026-90978/ (Markdown: https://insights.sbomify.com/CVE-2026-90978/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-90978
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-90978
- OSV: https://osv.dev/vulnerability/CVE-2026-90978

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-90978/
Summaries are generated and may contain mistakes; the official description above is the record.