CVE-2021-3866

5.4 mediumEPSS 0.9%

Medium (5.4) in zulip zulip. EPSS 0.9% chance of exploitation in the next 30 days.

Cross-site Scripting (XSS) - Stored in GitHub repository zulip/zulip more than and including 44f935695d452cc3fb16845a0c6af710438b153d and prior to 3eb2791c3e9695f7d37ffe84e0c2184fae665cb6.

Severity

CVSS 3.1

5.4 medium

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

EPSS: 0.9% chance of exploitation in the next 30 days; higher than 59% of CVEs (scores of 2026-10-31)
CWE: CWE-79
Published: 2022-01-20
Modified: 2026-06-17
Record from: the NVD, synced 2026-10-19

Affected

zulip:zulip

References

https://blog.zulip.com/2022/01/19/cve-2021-3866/
https://github.com/zulip/zulip/commit/3eb2791c3e9695f7d37ffe84e0c2184fae665cb6
https://huntr.dev/bounties/5f48dac5-e112-4b23-bbbf-cc00ba83bcf2
https://blog.zulip.com/2022/01/19/cve-2021-3866/
https://github.com/zulip/zulip/commit/3eb2791c3e9695f7d37ffe84e0c2184fae665cb6

Check your stack JSON