# CVE-2024-27286: Moving single messages from public to private streams leaves them accessible

> Attackers can view private messages moved from public streams due to stale client caches and missing permission revocations.

- **Severity:** Medium 6.5 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 20 Mar 2024
- **Updated:** 31 Mar 2025
- **Also known as:** GHSA-478x-rfqr-w4jf

## What is CVE-2024-27286?

CVE-2024-27286 is a medium-severity vulnerability in zulip, published on 20 Mar 2024. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Zulip is an open-source team collaboration tool. When a user moves a Zulip message, they have the option to move all messages in the topic, move only subsequent messages as well, or move just a single message.  If the user chose to just move one message, and was moving it from a public stream to a private stream, Zulip would successfully move the message, -- but active users who did not have access to the private stream, but whose client had already received the message, would continue to see the message in the public stream until they reloaded their client.  Additionally, Zulip did not remove view permissions on the message from recently-active users, allowing the message to show up in the "All messages" view or in search results, but not in "Inbox" or "Recent conversations" views. While the bug has been present since moving messages between streams was first introduced in version 3.0, this option became much more common starting in Zulip 8.0, when the default option in the picker for moving the very last message in a conversation was changed. This issue is fixed in Zulip Server 8.3. No known workarounds are available.

Weakness: CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor)

## Which versions are affected by CVE-2024-27286?

It affects 1 product.


Products: Zulip Zulip Server.

## How do I fix CVE-2024-27286?

No fix has been published for CVE-2024-27286 yet. Limit exposure of the affected software until one is available.

## Is CVE-2024-27286 being exploited?

There is no known exploitation of CVE-2024-27286 in the wild and no public exploit code.

## Other vulnerabilities in zulip

- [CVE-2019-18933](https://insights.sbomify.com/CVE-2019-18933/): Information disclosure in n/a (critical 9.8)
- [CVE-2020-15070](https://insights.sbomify.com/CVE-2020-15070/): Code injection in n/a (high 8.8)
- [CVE-2017-0910](https://insights.sbomify.com/CVE-2017-0910/): Missing authorization in Zulip Server (high 8.8)
- [CVE-2025-31478](https://insights.sbomify.com/CVE-2025-31478/): Zulip Authentication Backend Configuration Bypass (high 8.2)
- [CVE-2023-33186](https://insights.sbomify.com/CVE-2023-33186/): Cross-site scripting vulnerability in Zulip Server development branch via topic tooltip (high 8.2)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-27286 and fix it if it is affected.

What it is: CVE-2024-27286 is a medium-severity vulnerability in zulip, published on 20 Mar 2024. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2024-27286 in the wild and no public exploit code.

Affected product: zulip. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2024-27286/ (Markdown: https://insights.sbomify.com/CVE-2024-27286/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-27286
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-27286
- OSV: https://osv.dev/vulnerability/CVE-2024-27286

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-27286/
Summaries are generated and may contain mistakes; the official description above is the record.