Is CVE-2026-45677 in the CISA KEV catalog?

No. CVE-2026-45677 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2026-45677?

CVE-2026-45677 has a CVSS v4 base score of 8.7 (HIGH).

What is the EPSS score for CVE-2026-45677?

CVE-2026-45677 has an EPSS score of 0.45% (36th percentile), estimating the probability of exploitation in the next 30 days.

CVE & CISA-KEV Catalog

CVE-2026-45677

HIGH

8.7

CVSS v4

NVD

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.

CWE-862Missing Authorization

CVSS v4 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

Impact

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Exploit Intelligence

0.45%probability of exploitation in 30 days

36thpercentile

Low risk: more likely to be exploited than 36% of all known CVEs.

References

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

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-06-25.