Report · SecurityWeekAbout CVE-2026-41709Published 29 Oct 2026

Chinese Hackers Quietly Used Low-Severity ESXi Logging Flaw as Zero-Day

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Authoritative record:CVE-2026-41709· Low 2.7

Exploited in the wild · KEV due 11 Nov 2026 · fixed in 5.2.4 : patch ESX now.

Data as of 29 Oct 2026, 08:10 UTC

CVSS 3.1 base score

2.7Low

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

Thin evidence

One scorer or none

CVSS scores by source
CNA (vmware)	CVSS 3.1	2.7

KEV deadline: 11 Nov 2026 US federal agencies must patch by this date; a sensible deadline for everyone else. Other KEV due dates
Patch: Available – fixed in 5.2.4, ESXi80U3j-25429389, ESXi-9.1.0.0-25370933 +1

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: High
User Interaction: None
Scope: Unchanged
Confidentiality: None
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: High: The attacker is authorized with (i.e., requires) privileges that provide significant (e.g., administrative) control over the vulnerable component that could affect component-wide settings and files.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
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: None: There is no loss of confidentiality within 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

t = 0 is the CVE’s publication on cve.org

Disclosed: evidence found.
CVE published 30 Jul 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: evidence found.
Listed in CISA KEV 90 days after disclosure
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

CVE ID reserved
by VMware by Broadcom
22 Apr 202606:21 UTC, 99 days before disclosure
CVE published
on cve.org
30 Jul 202612:45 UTC, t = 0
In Threat Radar
record ingested
30 Jul 202613:22 UTC, 38 minutes after disclosure
Added to CISA KEV (opens in a new tab)
exploitation confirmed
28 Oct 2026, 90 days after disclosure
KEV remediation due
US federal deadline
11 Nov 2026, 104 days after disclosure

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), CISA KEV (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 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.

zero-day

What to do

Upgrade ESX to ESXi80U3j-25429389, ESXi-9.1.0.0-25370933 or ESXi-9.0.2.0100-25595025; Cloud Foundation to 5.2.4.

Affected software

Product	Affected	Fixed in
VMwareCloud Foundation	Affected >=5.x <5.2.4 =9.1.x.x =9.0.x.x	Fixed in 5.2.4
VMwarevSphere Foundation	Affected =9.1.x.x =9.0.x.x	Fixed in–
VMwareESX	Affected =9.1.x.x =9.0.x.x =8.0	Fixed in ESXi80U3j-25429389 ESXi-9.1.0.0-25370933 ESXi-9.0.2.0100-25595025
VMwareTelco Cloud Platform	Affected =>=5.1.0 <5.2.0 =>=5.0.0 <5.1.0	Fixed in–

AI-suggested

VMware has released patches addressing CVE-2026-41709 in ESXi versions 9.1.0.0-25370933, 9.0.2.0100-25595025, 80U3j-25429389, and newer. Organizations should apply these updates promptly. CISA has added this vulnerability to its Known Exploited Vulnerabilities catalog and recommends patching within two weeks. No alternative mitigations or workarounds are indicated. Since the vulnerability requires administrative access, limiting and monitoring administrative privileges remains a best practice but is not a direct mitigation for this flaw.

Description

CVE-2026-41709 is a low-severity vulnerability in VMware ESXi that allows attackers with administrative privileges to perform certain operations without those actions being logged. This flaw reduces audit trail visibility, which can aid attackers in hiding their activities. The vulnerability was exploited as a zero-day by the China-linked threat actor Warp Panda in intrusions targeting US organizations, including law firms. VMware has released patches for ESXi versions 9.1.0.0-25370933, 9.0.2.0100-25595025, and 80U3j-25429389 and newer. The US Cybersecurity and Infrastructure Security Agency (CISA) has added this vulnerability to its Known Exploited Vulnerabilities catalog and urges prompt patching.

Impact

The vulnerability allows attackers with administrative privileges to perform operations on VMware ESXi hosts without those actions being logged, significantly reducing audit trail visibility. This can hinder detection and forensic analysis of malicious activities. Although the flaw itself is low severity, its exploitation as a zero-day by a sophisticated threat actor demonstrates its utility in advanced persistent threat campaigns. The impact is primarily on security monitoring and incident response capabilities rather than direct system compromise.

Summary

CVE-2026-41709 is an insufficient logging vulnerability in VMware ESXi that permits attackers with administrative access to perform operations without generating logs, thereby reducing audit trail visibility. This vulnerability was disclosed on July 29, 2026, alongside other critical VMware vulnerabilities. The China-nexus threat actor Warp Panda exploited this flaw as a zero-day in attacks against US organizations, leveraging it to conceal malicious activity. VMware patched the issue in ESXi versions 9.1.0.0-25370933, 9.0.2.0100-25595025, and 80U3j-25429389 and later. CISA has included this vulnerability in its KEV catalog and recommends patching within two weeks. While the vulnerability is rated low severity, its exploitation in the wild for stealth purposes underscores its operational impact.

References

securityweek.com/chinese-hackers-quietly-used-low-severity-esxi-logging-flaw-as-zero-day/ (opens in a new tab)

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Exploitation evidence

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Affected software

Description

AI analysisMachine-generated, updated 29 Oct 2026, 08:10 UTC

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