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).
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Telegram Telegram Desktop
Default version status: unaffected
4.15.1 to < 6.9.4affected
References
- https://github.com/telegramdesktop/tdesktop/commit/8457d13aa795fadf99c955d2a04f00ebc3c59df9 ↗
- https://github.com/telegramdesktop/tdesktop/commit/52c779bffa8dde3c5c09826add2607328fae0924 ↗
- https://github.com/telegramdesktop/tdesktop/releases/tag/v6.9.4 ↗
- 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 ↗
- https://thehackernews.com/2026/09/telegram-desktop-flaw-lets-hidden.html ↗