XSS in Telegram Desktop
CVE-2026-94488
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).
Vulnerability class: XSS (Cross-Site Scripting)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.2 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N.
EPSS exploit prediction
EPSS: 0.001 (3.3th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 3rd percentile — 3.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.001 · change: -0.001
Affected products
Weakness classification (CWE)
References
- github.com/telegramdesktop/tdesktop/commit/8457d13aa795fadf99c955d2a04f00ebc3c5… (patch)
- github.com/telegramdesktop/tdesktop/commit/52c779bffa8dde3c5c09826add2607328fae… (related)
- github.com/telegramdesktop/tdesktop/releases/tag/v6.9.4 (release-notes)
- github.com/telegramdesktop/tdesktop/blob/v6.9.3/Telegram/SourceFiles/export/out… (related)
- expatch.com/writeups/telegram-html-export-xss.html (technical-description, exploit, third-party-advisory)
- thehackernews.com/2026/09/telegram-desktop-flaw-lets-hidden.html (media-coverage)
Frequently asked questions
- What is CVE-2026-94488?
- CVE-2026-94488 is a high-severity vulnerability in Telegram Desktop, classified under Cross-site Scripting. CVSS score: 8.2/10. Published 2026-09-21.
- How severe is CVE-2026-94488?
- High severity. CVSS v3 base score is 8.2 out of 10.