What is CVE-2021-37596?

CVE-2021-37596 is a medium-severity vulnerability in Telegram Web K Alpha, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2021-07-30.

How severe is CVE-2021-37596?

Medium severity. CVSS v3 base score is 6.1 out of 10.

XSS in Telegram Web K Alpha

CVE-2021-37596

Telegram Web K Alpha 0.6.1 allows XSS via a document name.

Vulnerability class: XSS (Cross-Site Scripting)

Published 2021-07-30 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.006 (49.7th percentile), scored 2026-11-01.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 50th percentile — 49.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: 0.000

Affected products

Telegram Web K Alpha — versions 0.6.1

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

github.com/morethanwords/tweb/commit/11d2fe01363889f20c8baa2217ed4aad445c5551 (Patch, Third Party Advisory)

Frequently asked questions

What is CVE-2021-37596?: CVE-2021-37596 is a medium-severity vulnerability in Telegram Web K Alpha, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2021-07-30.
How severe is CVE-2021-37596?: Medium severity. CVSS v3 base score is 6.1 out of 10.