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Emissary CVE-2021-32634

HIGH
Deserialization of Untrusted Data (CWE-502)
2021-05-21 security-advisories@github.com
7.2
CVSS 3.1 · NVD
View

Vulnerability Assessment

Weakness
CWE
OWASP Top 10:2025
A08:2025 - Software or Data Integrity Failures
ASVS 5.0
V1 - Encoding and Sanitization Safe deserialization, type allowlists
MITRE ATT&CK

2 techniques across 2 tactics: Execution, Initial Access

The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up.

Impact

CVSS score of 7.2 (HIGH). Attack characteristics: network attack vector, low complexity, high privileges required, no user interaction not required.

Exploit ScenarioDerived

A remote attacker could execute arbitrary code through malicious serialized objects by sending crafted requests to the affected application.

This Week Schedule remediation this week. Why: HIGH severity (CVSS 7.0-8.9).
Patch available 1.3% exploitation probability (EPSS)

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AnalysisAI

Emissary is a distributed, peer-to-peer, data-driven workflow framework. Rated high severity (CVSS 7.2), this vulnerability is remotely exploitable, low attack complexity. This Deserialization of Untrusted Data vulnerability could allow attackers to execute arbitrary code through malicious serialized objects.

RemediationAI

A vendor patch is available. Apply the latest security update as soon as possible. Avoid deserializing untrusted data. Use safe serialization formats (JSON). Implement integrity checks and type allowlists.

Affects your stack

Find out whether the stacks and servers you run are on an affected version.

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

This vulnerability is classified as Deserialization of Untrusted Data (CWE-502), which allows attackers to execute arbitrary code through malicious serialized objects. Emissary is a distributed, peer-to-peer, data-driven workflow framework. Emissary 6.4.0 is vulnerable to Unsafe Deserialization of post-authenticated requests to the WorkSpaceClientEnqueue.action REST endpoint. This issue may lead to post-auth Remote Code Execution. This issue has been patched in version 6.5.0. As a workaround, one can disable network access to Emissary from untrusted sources. Affected products include: Nsa Emissary. Version information: version 6.5.0..

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  • Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

NVD PRIMARY 7.2 HIGH
AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

Attack Vector
Network
Attack Complexity
Low
Privileges Required
High
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

DescriptionNVD

Emissary is a distributed, peer-to-peer, data-driven workflow framework. Emissary 6.4.0 is vulnerable to Unsafe Deserialization of post-authenticated requests to the WorkSpaceClientEnqueue.action REST endpoint. This issue may lead to post-auth Remote Code Execution. This issue has been patched in version 6.5.0. As a workaround, one can disable network access to Emissary from untrusted sources.

Threat Intelligence Overview

EPSS Score
1.3%
Top 33% exploitable
Data Quality
3 sources
Confidence: Low

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue
Severity HIGH
CISA KEV No
Public POC No
EPSS 1.3%
Patch available Yes
Active threat No
Deciding rule
HIGH severity (CVSS 7.0-8.9)
What every action level means
Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.
Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.
This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.
This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.
Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived
Scheduled
Exploitation· derived
None
System Exposure· derived
Open
Automatable· derived
No
Human Impact· derived
Medium

Priority Score

37
Low Medium High Critical
KEV: 0
EPSS: +1
CVSS: +36
PoC: 0
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

Insecure deserialization occurs when an application converts serialized data (a stream of bytes representing an object's state) back into a living object without proper validation.

Remote Code Execution represents the critical moment when an attacker successfully runs arbitrary code on a target system without physical access.

Affected Products (CPE)NVD

cpe:2.3:a:nsa:emissary:6.4.0:*:*:*:*:*:*:*
CVE-2021-32639 CRITICAL POC
9.9 Jul 02

Emissary is a P2P-based, data-driven workflow engine. Rated critical severity (CVSS 9.9), this vulnerability is remotely

CVE-2021-32647 CRITICAL POC
9.1 Jun 01

Emissary is a P2P based data-driven workflow engine. Rated critical severity (CVSS 9.1), this vulnerability is remotely

CVE-2021-32096 HIGH POC
8.8 May 07

The ConsoleAction component of U.S. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, no authe

CVE-2021-32093 MEDIUM POC
6.5 May 07

The ConfigFileAction component of U.S. Rated medium severity (CVSS 6.5), this vulnerability is remotely exploitable, low

CVE-2021-32092 MEDIUM POC
6.1 May 07

A Cross-site scripting (XSS) vulnerability in the DocumentAction component of U.S. Rated medium severity (CVSS 6.1), thi

CVE-2026-35580 CRITICAL
9.1 Apr 07

Shell command injection in Emissary workflow engine below version 8.39.0 allows high-privileged attackers with repositor

CVE-2021-32094 HIGH
8.8 May 07

U.S. Rated high severity (CVSS 8.8), this vulnerability is remotely exploitable, low attack complexity. No vendor patch

CVE-2021-32095 HIGH
8.1 May 07

U.S. Rated high severity (CVSS 8.1), this vulnerability is remotely exploitable, low attack complexity. No vendor patch

CVE-2026-35581 HIGH
7.2 Apr 07

Command injection in NSA Emissary P2P workflow engine (versions prior to 8.39.0) allows authenticated remote administrat

CVE-2026-35583 MEDIUM
5.3 Apr 07

Emissary versions prior to 8.39.0 allow unauthenticated remote attackers to read arbitrary configuration files through p

CVE-2026-35571 MEDIUM
4.8 Apr 07

Stored cross-site scripting in Emissary prior to 8.39.0 allows authenticated administrators to inject malicious javascri

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