CVE-2026-42294
CVE-2026-42294 — Argo Workflows: Unauthenticated Memory Exhaustion (DoS) in Webhook Interceptor
Argo Workflows is an open source container-native workflow engine for orchestrating parallel jobs on Kubernetes. Prior to versions 3.7.14 and 4.0.5, the Webhook Interceptor loads the entire request body into memory before authenticating the request or verifying its signature. This occurs on the /api/v1/events/ endpoint, which is publicly accessible (albeit intended for webhooks). An attacker can send a request with an extremely large body (e.g., multiple gigabytes), causing the Argo Server to allocate excessive memory, potentially leading to an Out-Of-Memory (OOM) crash and denial of service. This issue has been patched in versions 3.7.14 and 4.0.5.
Published Updated Sources: cvelistV5, GitHub_M
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the scoring sources call it.
Exploitation
Unreported
no source claims exploitation
EPSS
1%
chance of exploitation in 30 days
CVSS base
7.5
HIGH
CISA SSVC assessment
Three decision points CISA publishes for the CVEs it assesses · SSVC 2.0.3. A stakeholder decision, not a severity score.
Exploitation
PoC
none · proof-of-concept · active
Automatable
Yes
can an attacker script all four kill-chain steps
Technical impact
Partial
partial · total control of the vulnerable component
Affected scope
The catalog records vendors and products as separate lists, not pairs, so which product belongs to which vendor is not something this page can say.
Every base score collected
Sources score independently and disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Source |
|---|---|---|---|---|---|
| 7.5 | CVSS 3.1 | HIGH | — | — | cvelistV5 |
Weakness & attack patterns
- CWE-770
Attack patterns reported against this CVE. The ATT&CK techniques below are inferred from its weakness class.
- T1498.001Network Denial of Service: Direct Network Flood
- T1499Endpoint Denial of Service
- T1499.003Endpoint Denial of Service: Application Exhaustion Flood
Detection
Read off the CVSS vector and the weakness class. Starting points, not rules we have tested.
- Search application, proxy, and WAF logs for requests touching /api/v1/events/.
References
7 on the record
- github.com/argoproj/argo-workflows/security/advisories/GHSA-jcc8-g2q4-9fxq
x_refsource_CONFIRM
- github.com/argoproj/argo-workflows/commit/7abb4de6c3599e2d5d960ba4d5de4cf1df109965
x_refsource_MISC
- github.com/argoproj/argo-workflows/releases/tag/v3.7.14
x_refsource_MISC
- github.com/argoproj/argo-workflows/releases/tag/v4.0.5
x_refsource_MISC
- access.redhat.com/security/cve/CVE-2026-42294
vdb-entry, x_refsource_REDHAT
- bugzilla.redhat.com/show_bug.cgi?id=2468443
issue-tracking, x_refsource_REDHAT
- security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-42294.json
x_sadp-csaf-vex
Elsewhere on this site
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 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.