VulnerabilityPublished 12 Sep 2023Updated 30 Oct 2025

CVE-2023-36736: Microsoft Identity Linux Broker · Deserialization of Untrusted Data

Affects Microsoft Identity Linux BrokerSource CVE Database V5

Not known to be exploited · CVSS 4.4 Medium.

Data as of 26 Oct 2026, 14:05 UTC

CVSS 3.1 base score

4.4Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 1.3% chance of exploitation in 30 days – higher than 71% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N/E:U/RL:O/RC:C

Base metrics

Attack Vector: Local
Attack Complexity: Low
Privileges Required: None
User Interaction: Required
Scope: Unchanged
Confidentiality: Low
Integrity: Low
Availability: None

Temporal metrics

Exploit Code Maturity: Unproven
Remediation Level: Official Fix
Report Confidence: Confirmed

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Local: The vulnerable component is not bound to the network stack and the attacker’s path is via read/write/execute capabilities. Either: the attacker exploits the vulnerability by accessing the target system locally (e.g., keyboard, console), or remotely (e.g., SSH); or the attacker relies on User Interaction by another person to perform actions required to exploit the vulnerability (e.g., tricking a legitimate user into opening a malicious document).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: Required: Successful exploitation of this vulnerability requires a user to take some action before the vulnerability can be exploited.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: None: There is no impact to availability within the impacted component.
Exploit Code Maturity: Unproven: No exploit code is available, or an exploit is theoretical.
Remediation Level: Official Fix: A complete vendor solution is available. Either the vendor has issued an official patch, or an upgrade is available.
Report Confidence: Confirmed: Detailed reports exist, or functional reproduction is possible (functional exploits may provide this). Source code is available to independently verify the assertions of the research, or the author or vendor of the affected code has confirmed the presence of the vulnerability.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 12 Sep 2023
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
Microsoft Microsoft Identity Linux Broker	Affected =1.0.0	Fixed in–

AI-suggested

Monitor Microsoft’s official channels for patches or updates addressing CVE-2023-36736 and apply them promptly once available.
Restrict local access to systems running Microsoft Identity Linux Broker to trusted users only, employing strict access controls and least privilege principles.
Educate users about the risks of interacting with untrusted serialized data or suspicious files to reduce the likelihood of successful social engineering.
Implement application whitelisting and endpoint detection and response (EDR) solutions to detect anomalous deserialization activities or unexpected code execution attempts.
Conduct regular audits of systems running the affected software to identify unauthorized changes or suspicious behavior.
Consider isolating or sandboxing the Microsoft Identity Linux Broker process to limit the impact of potential exploitation.
Review and harden identity management configurations to minimize exposure of sensitive identity data on Linux systems.
Employ network segmentation to limit lateral movement if a system is compromised. These steps go beyond generic advice by focusing on access control, user awareness, monitoring, and containment specific to the nature of this deserialization vulnerability.

Description

Microsoft Identity Linux Broker Remote Code Execution Vulnerability

Impact

For European organizations, this vulnerability poses a risk primarily to Linux systems integrated with Microsoft identity services using the Microsoft Identity Linux Broker version 1.0.0. The potential impact includes unauthorized disclosure of sensitive identity-related information (confidentiality) and unauthorized modification of identity data or authentication flows (integrity). While availability is not affected, the ability to execute arbitrary code could allow attackers to establish persistence or move laterally within networks. Organizations with hybrid environments leveraging Microsoft identity solutions on Linux endpoints or servers are particularly at risk. The requirement for local access and user interaction limits remote exploitation but insider threats or social engineering attacks could exploit this vector. Given the widespread use of Linux in European enterprises, especially in sectors like finance, manufacturing, and government, the vulnerability could facilitate targeted attacks against critical infrastructure or sensitive data repositories. The medium severity rating suggests that while the threat is not immediately critical, it warrants timely attention to prevent escalation or exploitation in conjunction with other vulnerabilities.

CWE-502Deserialization of Untrusted Data (opens in a new tab)
Base weaknessLikelihood of exploit: MediumCWE Top 25 (2025): #15OWASP Top 10 A08:2025: Software or Data Integrity Failures (opens in a new tab)
The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.
Architecture and Design · Implementation
If available, use the signing/sealing features of the programming language to assure that deserialized data has not been tainted. For example, a hash-based message authentication code (HMAC) could be used to ensure that data has not been modified.
Implementation
When deserializing data, populate a new object rather than just deserializing. The result is that the data flows through safe input validation and that the functions are safe.
Implementation
Explicitly define a final object() to prevent deserialization.
OWASP Cheat Sheets
Abuse Case (opens in a new tab)
Deserialization (opens in a new tab)
XML Security (opens in a new tab)
XML External Entity Prevention (opens in a new tab)
Software Supply Chain Security (opens in a new tab)
OWASP ASVS 4.0.3
V1.5.2 (opens in a new tab)
V5.5.3 (opens in a new tab)
V5.5.1 (opens in a new tab)
Attack patterns
Object Injection (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

msrc.microsoft.com/update-guide/vulnerability/CVE-2023-36736 (opens in a new tab)

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 30 Oct 2025, 19:15 UTC

WeaknessesCWE-502

Technical details

References

Community reviews

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