CVE-2021-39880

What it is

A Denial Of Service vulnerability in the apollo_upload_server Ruby gem in GitLab CE/EE all versions starting from 11.9 before 14.0.9, all versions starting from 14.1 before 14.1.4, and all versions starting from 14.2 before 14.2.2 allows an attacker to deny access to all users via specially crafted requests to the apollo_upload_server middleware.

At a glance

Exploitability

Can be exploited over the network with a low-privilege account. High risk of service disruption.

Exploit odds

2.1% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2021-10-05 15:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 04:04 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 2.1% in the next 30 days (EPSS).
• Severity: 6.5 MEDIUM (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2021-10-05 15:15 UTC

Last modified

2026-06-17 04:04 UTC

Exploit probability

2.1% · EPSS, next 30 days

Record status

Modified

Affected

• GitLab < 14.0.9
• GitLab < 14.1.4
• GitLab < 14.2.2

Attack profile CVSS 3.1 · 6.5

Attack vector

Network

Complexity

Low

Privileges needed

Low

User interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2021-39880.md and follow it. Check whether this project is affected by CVE-2021-39880. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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