# CVE-2026-111609: PKP Open Journal Systems through 3.5.0-5 Cross-Journal Subscription IDOR via updateSubscription

> Journal managers can access and modify other journals' subscriptions by manipulating subscription IDs, leading to unauthorized data access and service disruption.

- **Severity:** Medium 5.1 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 16 Oct 2026
- **Updated:** 21 Oct 2026
- **Also known as:** GHSA-rwgq-cgw6-3p37

## What is CVE-2026-111609?

CVE-2026-111609 is a medium-severity missing authorization vulnerability in PKP Open Journal Systems, published on 16 Oct 2026. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

PKP Open Journal Systems through 3.5.0-5 contains an insecure direct object reference vulnerability that allows journal or subscription managers to access other journals' subscriptions by supplying arbitrary subscription ids. Attackers can enumerate sequential ids through editSubscription to view subscriber details and use updateSubscription to reassign subscriptions to their own journal, revoking victims' access.

Weakness: CWE-639 (Authorization Bypass Through User-Controlled Key)

## Which versions are affected by CVE-2026-111609?


## How do I fix CVE-2026-111609?

No fix has been published for CVE-2026-111609 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-111609 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-111609 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-111609 and fix it if it is affected.

What it is: CVE-2026-111609 is a medium-severity missing authorization vulnerability in PKP Open Journal Systems, published on 16 Oct 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-111609 exists.

Affected product: PKP Open Journal Systems. 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-2026-111609/ (Markdown: https://insights.sbomify.com/CVE-2026-111609/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-111609
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-111609
- OSV: https://osv.dev/vulnerability/CVE-2026-111609

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-111609/
Summaries are generated and may contain mistakes; the official description above is the record.