CVE-2021-47793 Telegram Desktop 2.9.2 - Denial of Service (PoC)

Medium 4.6 Published 15 Jan 2026 Updated 5 Mar 2026

Attackers can crash Telegram Desktop by pasting an oversized message payload, causing a denial of service for users.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Local or same network only
Victim action needed: A user has to click or open something
Fix: None listed

What is CVE-2021-47793?

CVE-2021-47793 is a medium-severity denial of service vulnerability in Telegram Desktop, published on 15 Jan 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.

Official description

Telegram Desktop 2.9.2 contains a denial of service vulnerability that allows attackers to crash the application by sending an oversized message payload. Attackers can generate a 9 million byte buffer and paste it into the messaging interface to trigger an application crash.

Weakness: CWE-770

Which versions are affected by CVE-2021-47793?

It affects 1 product.

Products include Telegram Telegram Desktop.

How do I fix CVE-2021-47793?

No fix has been published for CVE-2021-47793 yet. Limit exposure of the affected software until one is available.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2021-47793 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-47793 exists.

Sources

Also known as GHSA-4gqj-v3rw-hwjg.