CVE-2019-16215
The Markdown parser in Zulip server before 2.0.5 used a regular expression vulnerable to exponential backtracking.
Does this matter?
Lower severity and a low EPSS score (1.25%). Track it; it rarely justifies an emergency change on its own.
Description
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.
- CVSS 3.1
- 6.5 MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 1.25% probability · 69th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-1333
- Affected
- zulip/zulip server
- Source
- cve@mitre.org
EPSS 1.2% since 27 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://blog.zulip.org/2019/09/11/zulip-server-2-0-5-security-release/Vendor Advisory
- https://github.com/zulip/zulip/commit/5797f013b3be450c146a4141514bda525f2f1b51Patch, Third Party Advisory
- https://blog.zulip.org/2019/09/11/zulip-server-2-0-5-security-release/Vendor Advisory
- https://github.com/zulip/zulip/commit/5797f013b3be450c146a4141514bda525f2f1b51Patch, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.