# CVE-2026-30954: LinkAce has a Cross-User Tag/List Attachment IDOR in processTaxonomy()

> Authenticated users can attach other users' private tags and lists to their own links due to missing authorization checks in the taxonomy processing method.

- **Severity:** Medium 5.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA: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:** 10 Mar 2026
- **Updated:** 11 Mar 2026
- **Also known as:** GHSA-vc99-cgj6-wwxh

## What is CVE-2026-30954?

CVE-2026-30954 is a medium-severity missing authorization vulnerability in Kovah LinkAce, published on 10 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

LinkAce is a self-hosted archive to collect website links. In 2.1.0 and earlier, the processTaxonomy() method in LinkRepository.php allows authenticated users to attach other users' private tags and lists to their own links by passing integer IDs.

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

## Which versions are affected by CVE-2026-30954?

It affects 1 product.


Products: Linkace Linkace.

## How do I fix CVE-2026-30954?

No fix has been published for CVE-2026-30954 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-30954 being exploited?

There is no known exploitation of CVE-2026-30954 in the wild and no public exploit code.

## Other vulnerabilities in Kovah LinkAce

- [CVE-2026-27458](https://insights.sbomify.com/CVE-2026-27458/): LinkAce: Stored XSS in Atom Feed via CDATA Escape in List Description (high 8.7)
- [CVE-2025-62722](https://insights.sbomify.com/CVE-2025-62722/): LinkAce: Stored XSS Vulnerability in Link Title Field Through Social Media Sharing Feature (high 8.7)
- [CVE-2026-33953](https://insights.sbomify.com/CVE-2026-33953/): LinkAce's SSRF protection can be bypassed via internal hostname resolution in LinkAce (high 8.5)
- [CVE-2025-53838](https://insights.sbomify.com/CVE-2025-53838/): LinkAce has a Stored One Click XSS vulnerability (high 8.4)
- [CVE-2026-30953](https://insights.sbomify.com/CVE-2026-30953/): LinkAce affected by SSRF via link creation: NoPrivateIpRule not applied to LinkStoreRequest (high 7.7)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-30954 and fix it if it is affected.

What it is: CVE-2026-30954 is a medium-severity missing authorization vulnerability in Kovah LinkAce, published on 10 Mar 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-2026-30954 in the wild and no public exploit code.

Affected product: Kovah LinkAce. 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-2026-30954/ (Markdown: https://insights.sbomify.com/CVE-2026-30954/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-30954
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-30954
- OSV: https://osv.dev/vulnerability/CVE-2026-30954

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-30954/
Summaries are generated and may contain mistakes; the official description above is the record.