How severe is CVE-2021-47793?

CVE-2021-47793 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2021-47793 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (36th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-47793?

CVE-2021-47793 affects Telegram Telegram Desktop. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-47793?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2021-47793 have an EU (EUVD) identifier?

Yes. CVE-2021-47793 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-3030.

When was CVE-2021-47793 published?

CVE-2021-47793 was published on 2026-01-16 and last updated on 2026-06-17.

CVE-2021-47793

CVE-2021-47793 is a high-severity vulnerability in Telegram Telegram Desktop with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-770.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v4: 4.6
EPSS exploit prediction: 0% (36th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-3030
Weakness: CWE-770
Affected product: Telegram Telegram Desktop
Published: 2026-01-16
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-2021-47793?: 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.
How severe is CVE-2021-47793?: CVE-2021-47793 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2021-47793 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (36th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-47793?: CVE-2021-47793 affects Telegram Telegram Desktop. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-47793?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2021-47793 have an EU (EUVD) identifier?: Yes. CVE-2021-47793 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-3030.
When was CVE-2021-47793 published?: CVE-2021-47793 was published on 2026-01-16 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:telegram:telegram_desktop:2.9.2:*:*:*:*:*:*:*

More vulnerabilities in Telegram Telegram Desktop

CVE-2018-17613 — Critical (CVSS 9.8): Telegram Desktop (aka tdesktop) 1.3.16 alpha, when "Use proxy" is enabled, sends credentials and application data in…
CVE-2019-10044 — High (CVSS 8.8): Telegram Desktop before 1.5.12 on Windows, and the Telegram applications for Android, iOS, and Linux, is vulnerable to…
CVE-2020-17448 — High (CVSS 7.8): Telegram Desktop through 2.1.13 allows a spoofed file type to bypass the Dangerous File Type Execution protection…
CVE-2018-17231 — High (CVSS 7.5): Telegram Desktop (aka tdesktop) 1.3.14 might allow attackers to cause a denial of service (assertion failure and…
CVE-2020-12474 — Medium (CVSS 6.5): Telegram Desktop through 2.0.1, Telegram through 6.0.1 for Android, and Telegram through 6.0.1 for iOS allow an IDN…
CVE-2018-17780 — Medium (CVSS 6.5): Telegram Desktop (aka tdesktop) 1.3.14, and Telegram 3.3.0.0 WP8.1 on Windows, leaks end-user public and private IP…

All CVEs affecting Telegram Telegram Desktop →

Other CWE-770 (Allocation of Resources Without Limits or Throttling) vulnerabilities

CVE-2026-31283 — Critical (CVSS 9.8): In Totara LMS v19.1.5 and before, the forgot password API does not implement rate limiting for the target email…
CVE-2020-37067 — Critical (CVSS 9.8): Filetto 1.0 FTP server contains a denial of service vulnerability in the FEAT command processing that allows attackers…
CVE-2021-47875 — Critical (CVSS 9.8): GeoGebra CAS Calculator 6.0.631.0 contains a denial of service vulnerability that allows attackers to crash the…
CVE-2025-11832 — Critical (CVSS 9.8): Allocation of Resources Without Limits or Throttling vulnerability in Azure Access Technology BLU-IC2, Azure Access…
CVE-2024-44241 — Critical (CVSS 9.8): The issue was addressed with improved bounds checks. This issue is fixed in iOS 18.1 and iPadOS 18.1, macOS Sequoia…
CVE-2022-3439 — Critical (CVSS 9.8): Allocation of Resources Without Limits or Throttling in GitHub repository ikus060/rdiffweb prior to 2.5.0.

Browse all CWE-770 (Allocation of Resources Without Limits or Throttling) vulnerabilities →