# CVE-2026-35173: Chyrp Lite has an IDOR via Mass Assignment in Post Model

> Authenticated users can modify other users' posts by manipulating internal properties, leading to unauthorized data modification and potential account takeover.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N`)
- **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:** 6 Apr 2026
- **Updated:** 6 Apr 2026
- **Also known as:** GHSA-8c3h-rh2j-fxr9

## What is CVE-2026-35173?

CVE-2026-35173 is a medium-severity missing authorization vulnerability in xenocrat chyrp-lite, published on 6 Apr 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Chyrp Lite is an ultra-lightweight blogging engine. Prior to 2026.01, an IDOR / Mass Assignment issue exists in the Post model that allows authenticated users with post editing permissions (Edit Post, Edit Draft, Edit Own Post, Edit Own Draft) to modify posts they do not own and do not have permission to edit. By passing internal class properties such as id into the post_attributes payload, an attacker can alter the object being instantiated. As a result, further actions are performed on another user’s post rather than the attacker’s own post, effectively enabling post takeover. This vulnerability is fixed in 2026.01.

Weakness: CWE-914 (Improper Control of Dynamically-Identified Variables), CWE-639 (Authorization Bypass Through User-Controlled Key)

## Which versions are affected by CVE-2026-35173?

It affects 1 product.


Products: Chyrplite Chyrp Lite.

## How do I fix CVE-2026-35173?

No fix has been published for CVE-2026-35173 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-35173 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-35173 exists.

## Other vulnerabilities in xenocrat chyrp-lite

- [CVE-2026-35174](https://insights.sbomify.com/CVE-2026-35174/): Chyrp Lite has a Path Traversal to Remote Code Execution (critical 9.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-35173 and fix it if it is affected.

What it is: CVE-2026-35173 is a medium-severity missing authorization vulnerability in xenocrat chyrp-lite, published on 6 Apr 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-2026-35173 exists.

Affected product: xenocrat chyrp-lite. 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-2026-35173/ (Markdown: https://insights.sbomify.com/CVE-2026-35173/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-35173
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-35173
- OSV: https://osv.dev/vulnerability/CVE-2026-35173

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-35173/
Summaries are generated and may contain mistakes; the official description above is the record.