CVE-2023-33186
Cross-site scripting vulnerability in Zulip Server development branch via topic tooltip
Zulip is an open-source team collaboration tool with unique topic-based threading that combines the best of email and chat to make remote work productive and delightful. The main development branch of Zulip Server from May 2, 2023 and later, including beta versions 7.0-beta1 and 7.0-beta2, is vulnerable to a cross-site scripting vulnerability in tooltips on the message feed. An attacker who can send messages could maliciously craft a topic for the message, such that a victim who hovers the tooltip for that topic in their message feed triggers execution of JavaScript code controlled by the attacker.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- Required
What an attacker can affect
- Confidentiality
- High
- Integrity
- Low
- Availability
- Low
Exploit likelihood
What each source reports
CVE List Score used
8.2
Cross-site scripting vulnerability in Zulip Server development branch via topic tooltip
Zulip is an open-source team collaboration tool with unique topic-based threading that combines the best of email and chat to make remote work productive and delightful. The main development branch of Zulip Server from May 2, 2023 and later, including beta versions 7.0-beta1 and 7.0-beta2, is vulnerable to a cross-site scripting vulnerability in tooltips on the message feed. An attacker who can send messages could maliciously craft a topic for the message, such that a victim who hovers the tooltip for that topic in their message feed triggers execution of JavaScript code controlled by the attacker.
- Record
CVE-2023-33186- CVSS 3.1
- 8.2 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:L/A:L - Weakness
- CWE-79
- Updated
- 2026-11-02
EUVDEUVD-2023-37368
8.2
Zulip is an open-source team collaboration tool with unique topic-based threading that combines the best of email and chat to make remote work productive and delightful. The main development branch of Zulip Server from May 2, 2023 and later, including beta versions 7.0-beta1 and 7.0-beta2, is vulnerable to a cross-site scripting vulnerability in tooltips on the message feed. An attacker who can send messages could maliciously craft a topic for the message, such that a victim who hovers the tooltip for that topic in their message feed triggers execution of JavaScript code controlled by the attacker.
- Record
EUVD-2023-37368- CVSS 3.1
- 8.2 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:L/A:L - Updated
- 2026-11-03
NVD
8.2
Zulip is an open-source team collaboration tool with unique topic-based threading that combines the best of email and chat to make remote work productive and delightful. The main development branch of Zulip Server from May 2, 2023 and later, including beta versions 7.0-beta1 and 7.0-beta2, is vulnerable to a cross-site scripting vulnerability in tooltips on the message feed. An attacker who can send messages could maliciously craft a topic for the message, such that a victim who hovers the tooltip for that topic in their message feed triggers execution of JavaScript code controlled by the attacker.
- Record
CVE-2023-33186- CVSS 3.1
- 8.2 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:L/A:L - CVSS 3.1
- 6.1 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
OSV
8.2
Cross-site scripting vulnerability in Zulip Server development branch via topic tooltip
Zulip is an open-source team collaboration tool with unique topic-based threading that combines the best of email and chat to make remote work productive and delightful. The main development branch of Zulip Server from May 2, 2023 and later, including beta versions 7.0-beta1 and 7.0-beta2, is vulnerable to a cross-site scripting vulnerability in tooltips on the message feed. An attacker who can send messages could maliciously craft a topic for the message, such that a victim who hovers the tooltip for that topic in their message feed triggers execution of JavaScript code controlled by the attacker.
- Record
CVE-2023-33186- CVSS 3.1
- 8.2 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:L/A:L - Weakness
- CWE-79
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases, published | EUVD | |
| first indexed | CVE List, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2023-33186 is a high vulnerability (CVSS 8.2) in Zulip, published May 30, 2023. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.62%, the 49th percentile. No source names a fixed version.
References
github.com/zulip/zulip/security/advisories/GHSA-4r83-8f94-hrph
github.com/zulip/zulip/pull/25370
github.com/zulip/zulip/commit/03cfb3d9fe61c975d133121ec31a7357f0c9e18f
github.com/zulip/zulip/commit/3ca131743b00f42bad8edbac4ef92656d954c629
github.com/CVEProject/cvelistV5/tree/main/cves/2023/33xxx/CVE-2023-33186.json
nvd.nist.gov/vuln/detail/CVE-2023-33186