CVE-2026-45688

CVE-2026-45688 is a critical-severity vulnerability with a CVSS 3.x base score of 9.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-943.

Key facts

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 CAS login handler forwards the client-supplied options.cas.credentialToken value straight into a MongoDB findOne({_id: ...}) query without any runtime type check. TypeScript's string parameter annotation is erased at runtime, so an unauthenticated attacker can substitute a MongoDB query operator ({"$gt": ""}, {"$ne": null}, etc.) for what the server expects to be an opaque ticket string. The injected operator matches the first unexpired document in the credential_tokens collection, bypassing the CAS ticket check entirely. When any legitimate CAS or SAML SSO login is in flight, the attacker's next DDP login call matches the same credential-token row via the NoSQL operator and is issued a full Meteor auth token (userId + token) bound to the victim. The token is immediately usable against the complete REST and DDP surface as that user. If the victim is an administrator, this escalates to full instance compromise via Apps-Engine app install. 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.

Frequently asked questions

What is CVE-2026-45688?
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 CAS login handler forwards the client-supplied options.cas.credentialToken value straight into a MongoDB findOne({_id: ...}) query without any runtime type check. TypeScript's string parameter annotation is erased at runtime, so an unauthenticated attacker can substitute a MongoDB query operator ({"$gt": ""}, {"$ne": null}, etc.) for what the server expects to be an opaque ticket string. The injected operator matches the first unexpired document in the credential_tokens collection, bypassing the CAS ticket check entirely. When any legitimate CAS or SAML SSO login is in flight, the attacker's next DDP login call matches the same credential-token row via the NoSQL operator and is issued a full Meteor auth token (userId + token) bound to the victim. The token is immediately usable against the complete REST and DDP surface as that user. If the victim is an administrator, this escalates to full instance compromise via Apps-Engine app install. 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.
How severe is CVE-2026-45688?
CVE-2026-45688 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.
Is CVE-2026-45688 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (21st percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-45688?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2026-45688 have an EU (EUVD) identifier?
Yes. CVE-2026-45688 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-39093.
When was CVE-2026-45688 published?
CVE-2026-45688 was published on 2026-06-24 and last updated on 2026-06-26.

References

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