CVE-2026-77798Network attack vectorHinoki check available

Authenticated service hang via retained user-manager lock

Published Sep 24, 2026 · Updated Sep 24, 2026

Deadlock in Rapid7 Velociraptor before 0.77.2 allows remote authenticated users to hang the Linux server through user messaging. The user manager returns when a requested user is absent without releasing its mutex, leaving later user-management operations blocked. An authenticated account must reach the user-message path; successful exploitation interrupts server operations rather than disclosing or altering data.

CVSS severityUnavailable
Unscored
EPSS probability0.20%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Deadlock in Rapid7 Velociraptor before 0.77.2 allows remote authenticated users to hang the Linux server through user messaging. The user manager returns when a requested user is absent without releasing its mutex, leaving later user-management operations blocked. An authenticated account must reach the user-message path; successful exploitation interrupts server operations rather than disclosing or altering data.

The record

CVE
CVE-2026-77798
Published
Sep 24, 2026
Updated
Sep 24, 2026
Vendor
Rapid7
Product
Velociraptor
Classifications
CWE-833, T1499
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Sep 24, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 24, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <0.77.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Rapid7 · Velociraptorversion=0 <0.77.2

Published CVSS scores

No CVSS assessment is available in this record.

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-833Deadlock
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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