What is CVE-2021-27205?

CVE-2021-27205 is a medium-severity vulnerability in Apple macOS, classified under Cleartext Storage of Sensitive Information. CVSS score: 5.5/10. Published 2021-02-12.

How severe is CVE-2021-27205?

Medium severity. CVSS v3 base score is 5.5 out of 10.

Vulnerability in Apple macOS

CVE-2021-27205

Telegram before 7.4 (212543) Stable on macOS stores the local copy of self-destructed messages in a sandbox path, leading to sensitive information disclosure.

Published 2021-02-12 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.003 (19.8th percentile), scored 2026-10-01.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 20th percentile — 19.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000

Affected products

Weakness classification (CWE)

CWE-312 — Cleartext Storage of Sensitive Information

References

www.inputzero.io/2020/12/telegram-privacy-fails-again.html (Third Party Advisory)
www.youtube.com/watch (Exploit, Third Party Advisory)

Frequently asked questions

What is CVE-2021-27205?: CVE-2021-27205 is a medium-severity vulnerability in Apple macOS, classified under Cleartext Storage of Sensitive Information. CVSS score: 5.5/10. Published 2021-02-12.
How severe is CVE-2021-27205?: Medium severity. CVSS v3 base score is 5.5 out of 10.