# CVE-2026-88916: Admin Access Bypass via Header Fallback in TÜBİTAK ULAKBİM's UlakPDF

> Attackers can bypass admin authentication via header fallback to gain privileged access in UlakPDF.

- **Severity:** Medium 6.8 (`CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/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:** 24 Sep 2026
- **Updated:** 24 Sep 2026
- **Also known as:** GHSA-6gp4-g9px-6pmh

## What is CVE-2026-88916?

CVE-2026-88916 is a medium-severity authentication bypass vulnerability in TÜBİTAK ULAKBİM UlakPDF, published on 24 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Incorrect Authorization vulnerability in TÜBİTAK ULAKBİM UlakPDF allows Privilege Escalation.

This issue affects UlakPDF: through 09092026.

Weakness: CWE-863 (Incorrect Authorization)

## Which versions are affected by CVE-2026-88916?


## How do I fix CVE-2026-88916?

No fix has been published for CVE-2026-88916 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-88916 being exploited?

There is no known exploitation of CVE-2026-88916 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-88916 and fix it if it is affected.

What it is: CVE-2026-88916 is a medium-severity authentication bypass vulnerability in TÜBİTAK ULAKBİM UlakPDF, published on 24 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-2026-88916 in the wild and no public exploit code.

Affected product: TÜBİTAK ULAKBİM UlakPDF. 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-2026-88916/ (Markdown: https://insights.sbomify.com/CVE-2026-88916/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-88916
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-88916
- OSV: https://osv.dev/vulnerability/CVE-2026-88916

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From sbomify Insights: https://insights.sbomify.com/CVE-2026-88916/
Summaries are generated and may contain mistakes; the official description above is the record.