What is CVE-2019-19775?

CVE-2019-19775 is a medium-severity vulnerability in Zulip Server, classified under URL Redirection to Untrusted Site (Open Redirect). CVSS score: 6.1/10. Published 2019-12-18.

How severe is CVE-2019-19775?

Medium severity. CVSS v3 base score is 6.1 out of 10.

Is CVE-2019-19775 known to be exploited?

3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Open Redirect in Zulip Server

CVE-2019-19775

The image thumbnailing handler in Zulip Server versions 1.9.0 to before 2.0.8 allowed an open redirect that was visible to logged-in users.

Vulnerability class: Open Redirect

Published 2019-12-18 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.009 (58.2th percentile), scored 2026-10-23.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 58th percentile — 58.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.009 · newest: 0.009 · change: 0.000

Affected products

Zulip Server

Weakness classification (CWE)

CWE-601 — URL Redirection to Untrusted Site (Open Redirect)

Public proof-of-concept exploits

References

github.com/zulip/zulip/commit/b7c87a4d82397a5e6ac169b6098bed0b1ae7a583 (Patch, Third Party Advisory)
blog.zulip.org/2019/12/13/zulip-server-2-0-8-security-release/ (Release Notes, Vendor Advisory)

Frequently asked questions

What is CVE-2019-19775?: CVE-2019-19775 is a medium-severity vulnerability in Zulip Server, classified under URL Redirection to Untrusted Site (Open Redirect). CVSS score: 6.1/10. Published 2019-12-18.
How severe is CVE-2019-19775?: Medium severity. CVSS v3 base score is 6.1 out of 10.
Is CVE-2019-19775 known to be exploited?: 3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.