High Access control

CVE-2026-93991 — Argo Workflows 4.1.0 through 4.1.3 Cross-Namespace Disclosure via Negated Selector

Argo Workflows versions 4.1.0 through 4.1.3 contain an authorization bypass vulnerability in ListArchivedWorkflows that fails to apply cluster-scoped access review when the metadata.namespace field selector uses the NotEquals operator. Attackers with namespace-scoped list permissions can use a negated namespace field selector to retrieve archived workflows from all other namespaces, exposing spec arguments, parameter values, and annotations.

Published Sep 19, 2026 · Updated Oct 15, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: VulnCheck

Low

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.

How the score was calculated

EPSS 0.4% (30-day exploitation probability)+5
Technical severity (high)+6

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation

Not confirmed

Not in CISA KEV — an absence of record, not proof it is unexploited.

EPSS FIRST

0.44%

ahead of 36% of scored CVEs · Oct 15, 2026

Affects

Argoproj

Argo Workflows

CVSS base

7.7

High · 2 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation

None

none · proof-of-concept · active

Automatable

can an attacker script the kill-chain steps

Technical impact

Partial

partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

Identify exposed assets running the affected vendor/product/version combinations (Argoproj Argo Workflows).
No fix documented in the sources: reduce exposure and monitor the vendor advisory.
Search available logs for exploit probes matching the vulnerability class (access control), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

Vendor	Product	Versions	Status	Source
Argoproj	Argo Workflows	≥ 4.1.0 and < 4.1.4	Vulnerable	CVE Program (cve.org) e CISA ADP

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector

Network

Attack complexity

Low

Privileges required

Low

User interaction

None

Scope

Changed

Confidentiality

High

Integrity

None

Availability

None

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Scored by
8.3	CVSS 4.0	High	—	—	disclosure@vulncheck.com via NIST National Vulnerability Database
8.3	CVSS 4.0	High	—	—	VulnCheck via CVE Program (cve.org) e CISA ADP
7.7	CVSS 3.1	High	3.1	4.0	disclosure@vulncheck.com via NIST National Vulnerability Database
7.7	CVSS 3.1	High	—	—	VulnCheck via CVE Program (cve.org) e CISA ADP

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N (score shown at the top: disclosure@vulncheck.com)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-639 · Authorization Bypass Through User-Controlled Key (IDOR)

Other CVEs with this weakness →

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
Audit administrative actions and access to resources outside each user’s normal pattern.

web/proxy/WAF logsnetwork IDS/IPSauthentication logsapplication logs

Timeline

What happened to this CVE, newest first.

2026
Affected products added · argoproj/argo-workflows
Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
SSVC assessment updated
Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
Record published
Oct 15, 2026
CVSS changed · 7.7
Oct 15, 2026 · NIST National Vulnerability Database
Source status changed · → Awaiting Analysis
Oct 15, 2026 · NIST National Vulnerability Database
Record created in this database
Oct 15, 2026 · NIST National Vulnerability Database
CVE published
Sep 19, 2026 · VulnCheck

Source activity

Repeated readings are counted rather than listed.

1× Official description updated · Oct 15, 2026 – Oct 15, 2026

References

5 on the record

github.com/argoproj/argo-workflows/commit/a40972386c097ddf816d2e60e13f058bedca53
patch, NIST National Vulnerability Database
www.vulncheck.com/advisories/argo-workflows-4.1.0-through-4.1.3-cross-namespace-disclos
third-party-advisory, NIST National Vulnerability Database
github.com/argoproj/argo-workflows
product, NIST National Vulnerability Database
github.com/argoproj/argo-workflows/security/advisories/GHSA-q65w-j2vp-47c4
vendor-advisory, NIST National Vulnerability Database
github.com/argoproj/argo-workflows/releases/tag/v4.1.4
release-notes, NIST National Vulnerability Database

Elsewhere on this site

Argoproj
every CVE for this vendor

Access control
same class

CWE-639
other pages naming this weakness

Related CVEs (same products)

Critical CVE-2026-54526 Argo Workflows: Incomplete fix for CVE-2026-31892: ArtifactGC.PodSpecPatch bypass of Strict/Secure templateReferencing Jul 16, 2026
Medium CVE-2026-42295 Argo Workflows: Exposure of artifact repository credentials May 9, 2026
High CVE-2026-42296 Argo Workflows has incomplete fix for CVE-2026-31892: hostNetwork, securityContext, serviceAccountName bypass templateReferencing Strict/Secure May 9, 2026
High CVE-2026-42297 Argo Workflows Is Missing Authorization in Sync ConfigMap Provider May 9, 2026
High CVE-2026-42294 Argo Workflows: Unauthenticated Memory Exhaustion (DoS) in Webhook Interceptor May 9, 2026
Medium CVE-2026-42183 Argo Workflows: SSO RBAC Delegation Nil Pointer Dereference DoS (gatekeeper.go) May 9, 2026

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No fixed version, patch or mitigation documented.
No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-93991 is "Argo Workflows 4.1.0 through 4.1.3 Cross-Namespace Disclosure via Negated Selector", rated High. It affects Argo Workflows (Argoproj); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 7.7 describes technical severity. EPSS 0.44% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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