CVE-2019-16215

6.5 mediumEPSS 1.2%

Medium (6.5) in zulip zulip server. EPSS 1.2% chance of exploitation in the next 30 days.

The Markdown parser in Zulip server before 2.0.5 used a regular expression vulnerable to exponential backtracking. A user who is logged into the server could send a crafted message causing the server to spend an effectively arbitrary amount of CPU time and stall the processing of future messages.

Severity

CVSS 3.1

6.5 medium

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

EPSS: 1.2% chance of exploitation in the next 30 days; higher than 69% of CVEs (scores of 2026-10-31)
CWE: CWE-1333
Published: 2019-09-18
Modified: 2026-06-17
Record from: the NVD, synced 2026-10-19

Affected

zulip:zulip_server

References

https://blog.zulip.org/2019/09/11/zulip-server-2-0-5-security-release/
https://github.com/zulip/zulip/commit/5797f013b3be450c146a4141514bda525f2f1b51
https://blog.zulip.org/2019/09/11/zulip-server-2-0-5-security-release/
https://github.com/zulip/zulip/commit/5797f013b3be450c146a4141514bda525f2f1b51

Check your stack JSON