# CVE-2023-53878: Member Login Script 3.3 Client-Side Request Desynchronization Vulnerability

> Attackers can exploit HTTP request desynchronization in Member Login Script to bypass server-side request processing controls via crafted POST requests.

- **Severity:** Medium 6.9 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 15 Dec 2025
- **Updated:** 12 May 2026
- **Also known as:** GHSA-3855-8298-m4gc

## What is CVE-2023-53878?

CVE-2023-53878 is a medium-severity vulnerability in Phpjabbers Member Login Script, published on 15 Dec 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Member Login Script 3.3 contains a client-side desynchronization vulnerability that allows attackers to manipulate HTTP request handling by exploiting Content-Length header parsing. Attackers can send crafted POST requests with smuggled secondary requests to potentially bypass server-side request processing controls.

Weakness: CWE-444 (Inconsistent Interpretation of HTTP Requests)

## Which versions are affected by CVE-2023-53878?


## How do I fix CVE-2023-53878?

No fix has been published for CVE-2023-53878 yet. Limit exposure of the affected software until one is available.

## Is CVE-2023-53878 being exploited?

There is no known exploitation of CVE-2023-53878 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-53878 and fix it if it is affected.

What it is: CVE-2023-53878 is a medium-severity vulnerability in Phpjabbers Member Login Script, published on 15 Dec 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2023-53878 in the wild and no public exploit code.

Affected product: Phpjabbers Member Login Script. 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-2023-53878/ (Markdown: https://insights.sbomify.com/CVE-2023-53878/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-53878
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-53878
- OSV: https://osv.dev/vulnerability/CVE-2023-53878

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-53878/
Summaries are generated and may contain mistakes; the official description above is the record.