CVE-2021-47793Public exploit

Application crash via oversized compose buffer

Published Jan 15, 2026 · Updated Jan 15, 2026

Denial of service in Telegram Desktop 2.9.2 allows local users to crash the application by pasting an oversized message payload. The message composer accepts a 9,000,000-byte text buffer from the clipboard without enforcing a resource limit, exhausting application resources. Exploitation requires local interaction with the messaging interface and interrupts only the client process; no confidentiality or integrity impact is reported.

CVSS severity4.6
Medium
EPSS probability0.51%
Next 30 days · Sep 17, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Telegram Desktop 2.9.2 allows local users to crash the application by pasting an oversized message payload. The message composer accepts a 9,000,000-byte text buffer from the clipboard without enforcing a resource limit, exhausting application resources. Exploitation requires local interaction with the messaging interface and interrupts only the client process; no confidentiality or integrity impact is reported.

The record

CVE
CVE-2021-47793
Published
Jan 15, 2026
Updated
Jan 15, 2026
Vendor
Telegram
Product
Telegram Desktop
Classifications
CWE-770, T1499.004
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 15, 2026CVE publishedPublication date reported by the CVE source.
  2. Jan 15, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=2.9.2

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Telegram · Telegram Desktopversion=2.9.2

Published CVSS scores

7.5VulnCheckCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
4.6VulnCheckCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 11, 2026Sep 17, 2026
Latest reporting daySep 17, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-770Allocation of Resources Without Limits or Throttling
T1499.004Application or System Exploitation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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