CVE-2026-94488

high

Description

Telegram Desktop before 6.9.4 allows XSS in the HTML exporter. (The first fixed stable version is 7.0.1.) This occurs in button.text.toUtf8 in export_output_html.cpp. Exploitation cannot occur unless HTML export was used by a victim. However, the exploit payload can be exported if a message were forwarded into a group by a member (it is not necessary for the message author to be a member of a group).

References

https://thehackernews.com/2026/09/telegram-desktop-flaw-lets-hidden.html

https://github.com/telegramdesktop/tdesktop/releases/tag/v6.9.4

https://github.com/telegramdesktop/tdesktop/commit/8457d13aa795fadf99c955d2a04f00ebc3c59df9

https://github.com/telegramdesktop/tdesktop/commit/52c779bffa8dde3c5c09826add2607328fae0924

https://github.com/telegramdesktop/tdesktop/blob/v6.9.3/Telegram/SourceFiles/export/output/export_output_html.cpp

https://expatch.com/writeups/telegram-html-export-xss.html

Details

Source: Mitre, NVD

Published: 2026-09-21

Updated: 2026-09-22

Risk Information

CVSS v2

Base Score: 6.6

Vector: CVSS2#AV:L/AC:L/Au:N/C:C/I:C/A:N

Severity: Medium

CVSS v3

Base Score: 8.2

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

Severity: High

CVSS v4

Base Score: 8.3

Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N

Severity: High

EPSS

EPSS: 0.00138