VulnerabilityPublished 19 Feb 2026

CVE-2026-26964: windmill · Information Exposure

Affects windmillSource CVE Database V5

Not known to be exploited · CVSS 2.7 Low : upgrade to 1.635.0 when convenient.

Data as of 26 Oct 2026, 14:05 UTC

CVSS 3.1 base score

2.7Low

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

EPSS: 0.3% chance of exploitation in 30 days – higher than 24% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 1.635.0

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

Attack Vector: Network
Attack Complexity: Low
Privileges Required: High
User Interaction: None
Scope: Unchanged
Confidentiality: Low
Integrity: None
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: 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: None: There is no loss of integrity within 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 19 Feb 2026
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

Upgrade windmill to 1.635.0.

Affected software

Product	Affected	Fixed in
windmill-labswindmill	Affected <1.635.0	Fixed in 1.635.0

AI-suggested

Organizations should upgrade windmill to version 1.635.0 or later, where the vulnerability has been fixed by proper redaction of the Slack OAuth client secret for non-admin users. Until the upgrade can be applied, administrators should consider restricting the number of users with authenticated access to windmill workspaces, especially limiting non-admin users who do not require access to Slack integrations. Review and rotate Slack OAuth client secrets to invalidate any potentially exposed credentials. Implement monitoring and alerting for unusual OAuth token usage or Slack integration activity that could indicate misuse. Additionally, enforce strong authentication and access controls on windmill to reduce the risk of compromised user accounts. Evaluate the necessity of Slack integration within windmill and disable it if not required. Finally, audit workspace settings and logs regularly to detect unauthorized access attempts or suspicious behavior related to OAuth credentials.

Description

Windmill is an open-source developer platform for internal code: APIs, background jobs, workflows and UIs. Versions 1.634.6 and below allow non-admin users to obtain Slack OAuth client secrets, which should only be accessible to workspace administrators. The GET /api/w/{workspace}/workspaces/get_settings endpoint returns the slack_oauth_client_secret to any authenticated workspace member, regardless of their admin status. It is expected behavior for non-admin users see a redacted version of workspace settings, as some of them are necessary for the frontend to behave correctly even for non-admins. However, the Slack configuration should not be visible to non-admins. This is a legacy issue where the setting was stored as a plain value instead of using $variable indirection, and it was never added to the redaction logic. This issue has been fixed in version 1.635.0.

Impact

The primary impact of this vulnerability is the unauthorized disclosure of Slack OAuth client secrets to any authenticated non-admin user within a windmill workspace. This exposure compromises the confidentiality of sensitive credentials that are intended to be restricted to administrators. With access to the Slack OAuth client secret, an attacker could potentially impersonate the windmill application in Slack integrations, leading to unauthorized access to Slack workspace resources, data leakage, or manipulation of Slack-based workflows and notifications. Although the vulnerability does not affect system integrity or availability, the compromise of OAuth credentials can facilitate further attacks on the Slack workspace or connected systems. Organizations relying on windmill for internal development and automation, especially those integrating with Slack, face increased risk of credential theft and subsequent lateral movement or data exfiltration within their collaboration environment. The vulnerability affects all organizations using windmill versions prior to 1.635.0 that have Slack integrations enabled and allow multiple authenticated users with non-admin roles. Since exploitation requires only authenticated access, insider threats or compromised user accounts could leverage this flaw to escalate access to sensitive OAuth credentials.

CWE-200Exposure of Sensitive Information to an Unauthorized Actor (opens in a new tab)
Class weaknessLikelihood of exploit: HighCWE Top 25 (2025): #20OWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.
MITRE discourages mapping vulnerabilities to this broad entry; the root cause is usually a more specific weakness.
Architecture and Design · Separation of Privilege
Compartmentalize the system to have "safe" areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area.
OWASP Cheat Sheets
Error Handling (opens in a new tab)
Logging (opens in a new tab)
Authorization (opens in a new tab)
OWASP ASVS 4.0.3
V8.3.4 (opens in a new tab)
V14.3.3 (opens in a new tab)
V7.3.3 (opens in a new tab)
Attack patterns
Subverting Environment Variable Values (opens in a new tab)
ICMP Echo Request Ping (opens in a new tab)
TCP SYN Scan (opens in a new tab)
Enumerate Mail Exchange (MX) Records (opens in a new tab)
DNS Zone Transfers (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

Loading reviews…

Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 28 Feb 2026, 14:49 UTC

WeaknessesCWE-200

Technical details

References

Community reviews

Related threats