CVE-2021-31321

Name: CVE-2021-31321
Creator: NVD / NIST
Published: 2021-05-18T20:15:07.79+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.1/10EPSS 1.10%

Last modified Jun 17, 2026

CVE-2021-31321 is a high-severity vulnerability rated 7.1/10 on the CVSS scale. Telegram Android <7.1.0 (2090), Telegram iOS <7.1, and Telegram macOS <7.1 are affected by a Stack Based Overflow in the gray_split_cubic function of their custom fork of the rlottie library. A remote attacker might be able to overwrite Telegram's stack memory out-of-bounds on a victim device via a malicious animated sticker.. EPSS estimates a 1.10% chance of exploitation in the next 30 days.

Description

Telegram Android <7.1.0 (2090), Telegram iOS <7.1, and Telegram macOS <7.1 are affected by a Stack Based Overflow in the gray_split_cubic function of their custom fork of the rlottie library. A remote attacker might be able to overwrite Telegram's stack memory out-of-bounds on a victim device via a malicious animated sticker.

Metrics

CVSS 3.1

7.1/10

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H

EPSS Probability

1.10%

61.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-787

Affected Software

Vendor	Product	Versions
Telegram	Telegram	< 7.1.0

References

https://www.shielder.it/advisories/telegram-rlottie-gray_split_cubic-stack-buffer-overflow/Exploit, Third Party Advisory
https://www.shielder.it/blog/2021/02/hunting-for-bugs-in-telegrams-animated-stickers-remote-attack-surface/Exploit, Third Party Advisory
https://www.shielder.it/advisories/telegram-rlottie-gray_split_cubic-stack-buffer-overflow/Exploit, Third Party Advisory
https://www.shielder.it/blog/2021/02/hunting-for-bugs-in-telegrams-animated-stickers-remote-attack-surface/Exploit, Third Party Advisory

Timeline

Published: May 18, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-31321?

How severe is CVE-2021-31321?

CVE-2021-31321 has a CVSS score of 7.1/10 (HIGH severity). The EPSS model estimates a 1.10% probability of exploitation in the next 30 days.

How do I fix CVE-2021-31321?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-31321?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST