VulnerabilityPublished 31 Mar 2026

CVE-2026-22569: Zscaler Client Connector · Improper validation of unsafe equivalence in input

Affects Zscaler Client ConnectorSource CVE Database V5

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Not known to be exploited · CVSS 5.4 Medium : upgrade to 4.8.0.63 or 4.7.0.141 when convenient.

Data as of 30 Oct 2026, 11:52 UTC

CVSS 3.1 base score

5.4Medium

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

EPSS: 0.1% chance of exploitation in 30 days – higher than 8% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 4.8.0.63, 4.7.0.141

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

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

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

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
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.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 31 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 30 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.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), 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

Upgrade Zscaler Client Connector to 4.8.0.63 or 4.7.0.141.

Affected software

Product	Affected	Fixed in
ZscalerZscaler Client Connector	Affected >=4.8 <4.8.0.63	Fixed in 4.8.0.63
ZscalerZscaler Client Connector	Affected >=4.7 <4.7.0.141	Fixed in 4.7.0.141

AI-suggested

Since no patches are currently available, organizations should immediately audit and verify the startup configurations of Zscaler Client Connector versions 4.7 and 4.8 on Windows systems to ensure proper inspection settings are enforced. Administrators should review deployment scripts, group policies, and configuration management tools to detect and correct any misconfigurations. Implement monitoring to detect unusual traffic patterns or unexpected bypass of inspection. Consider temporarily restricting use of affected versions or deploying alternative inspection mechanisms where feasible. Engage with Zscaler support for guidance and to receive updates on forthcoming patches. Educate users to minimize unnecessary client restarts or configuration changes that could trigger the vulnerability. Maintain robust network segmentation and layered security controls to reduce the impact of any bypassed traffic.

Description

An incorrect startup configuration of affected versions of Zscaler Client Connector on Windows may cause a limited amount of traffic from being inspected under rare circumstances.

Impact

The primary impact of this vulnerability is the potential for a limited amount of network traffic to bypass inspection by the Zscaler Client Connector. This can lead to reduced visibility into network communications, increasing the risk that malicious payloads, data exfiltration, or policy violations go undetected. Confidentiality and integrity of data may be compromised if sensitive information is transmitted without inspection or if malicious modifications are not detected. However, the scope is limited to a subset of traffic and does not affect system availability. Organizations relying heavily on Zscaler for enforcing security policies and compliance controls may face increased risk of undetected threats or data leakage. The lack of known exploits reduces immediate risk, but the presence of this vulnerability in widely deployed enterprise security software means that attackers could develop exploits targeting this weakness. The impact is more pronounced in environments with high security requirements and sensitive data flows, such as financial services, healthcare, and government sectors.

CWE-1289Improper Validation of Unsafe Equivalence in Input (opens in a new tab)
Base weakness
The product receives an input value that is used as a resource identifier or other type of reference, but it does not validate or incorrectly validates that the input is equivalent to a potentially-unsafe value.
Implementation · Input Validation
Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
OWASP Cheat Sheets
XML Security (opens in a new tab)
Mass Assignment (opens in a new tab)
OWASP ASVS 4.0.3
V13.3.1 (opens in a new tab)
V5.1.4 (opens in a new tab)
V5.1.3 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

help.zscaler.com/zscaler-client-connector/client-connector-app-release-summary-2025 (opens in a new tab)

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 31 Mar 2026, 15:39 UTC

WeaknessesCWE-1289

Technical details

References

Community reviews

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