# CVE-2024-23826: Uploading an image with a specific filename causes a server-side DoS

> An authenticated user can cause a server-side denial of service on Windows by uploading an avatar with a large Unicode filename.

- **Severity:** Medium 6.8 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 29 Jan 2024
- **Updated:** 2 Jun 2025
- **Also known as:** GHSA-5vfc-v7hg-pvwm

## What is CVE-2024-23826?

CVE-2024-23826 is a medium-severity denial of service vulnerability in spbu-se spbu_se_site, published on 29 Jan 2024. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

spbu_se_site is the website of the Department of System Programming of St. Petersburg State University. Before 2024.01.29, when uploading an avatar image, an authenticated user may intentionally use a large Unicode filename which would lead to a server-side denial of service under Windows. This is due to no limitation of the length of the filename and the costly use of the Unicode normalization with the form NFKD on Windows OS.  This vulnerability was fixed in the 2024.01.29 release.

Weakness: CWE-770 (Allocation of Resources Without Limits or Throttling)

## Which versions are affected by CVE-2024-23826?

It affects 1 product.


Products: Se.math.spbu Spbu Se Site.

## How do I fix CVE-2024-23826?

No fix has been published for CVE-2024-23826 yet. Limit exposure of the affected software until one is available.

## Is CVE-2024-23826 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2024-23826 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-23826 and fix it if it is affected.

What it is: CVE-2024-23826 is a medium-severity denial of service vulnerability in spbu-se spbu_se_site, published on 29 Jan 2024. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2024-23826 exists.

Affected product: spbu-se spbu_se_site. 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-2024-23826/ (Markdown: https://insights.sbomify.com/CVE-2024-23826/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-23826
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-23826
- OSV: https://osv.dev/vulnerability/CVE-2024-23826

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-23826/
Summaries are generated and may contain mistakes; the official description above is the record.