# CVE-2026-45677: Rocket.Chat: Lack of SAML Signature Check During Logout Could Lead To DoS

> Unauthenticated attackers can force logout of SAML users by sending unsigned LogoutRequests, causing denial of service.

- **Severity:** High 8.7 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 24 Jun 2026
- **Updated:** 25 Jun 2026
- **Also known as:** GHSA-pw6f-q8ww-vqfq

## What is CVE-2026-45677?

CVE-2026-45677 is a high-severity missing authorization vulnerability in RocketChat Rocket.Chat, published on 24 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Rocket.Chat is an open-source, secure, fully customizable communications platform. Prior to 8.5.0, 8.4.1, 8.3.3, 8.2.3, 8.1.4, 8.0.5, 7.13.7, and 7.10.11, Rocket.Chat's SAML integration does not verify the signature on inbound LogoutRequest messages. An unauthenticated remote attacker who knows a target user's SAML NameID - which major identity providers (Okta, Google Workspace, Microsoft Entra ID, JumpCloud) expose as the user's email address - can craft a valid-looking unsigned LogoutRequest and submit it to the SP logout endpoint. The server processes it as legitimate, immediately destroying the victim's session. Because the attack requires no authentication and no interaction from the victim, it can be repeated in a loop against individual users or scripted across many accounts, effectively rendering the Rocket.Chat instance unusable for SAML-authenticated users. This vulnerability is fixed in 8.5.0, 8.4.1, 8.3.3, 8.2.3, 8.1.4, 8.0.5, 7.13.7, and 7.10.11.

Weakness: CWE-862 (Missing Authorization)

## Which versions are affected by CVE-2026-45677?


## How do I fix CVE-2026-45677?

No fix has been published for CVE-2026-45677 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-45677 being exploited?

There is no known exploitation of CVE-2026-45677 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-45677 and fix it if it is affected.

What it is: CVE-2026-45677 is a high-severity missing authorization vulnerability in RocketChat Rocket.Chat, published on 24 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-45677 in the wild and no public exploit code.

Affected product: RocketChat Rocket.Chat. 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-2026-45677/ (Markdown: https://insights.sbomify.com/CVE-2026-45677/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-45677
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-45677
- OSV: https://osv.dev/vulnerability/CVE-2026-45677

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-45677/
Summaries are generated and may contain mistakes; the official description above is the record.