CVE-2026-42294
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.61%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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.
- CVSS 4.0
- 8.2 HIGHCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 0.61% probability · 47th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-770
- Affected
- argoproj/argo workflows
- Source
- security-advisories@github.com
References
- https://github.com/argoproj/argo-workflows/commit/7abb4de6c3599e2d5d960ba4d5de4cf1df109965Patch
- https://github.com/argoproj/argo-workflows/releases/tag/v3.7.14Release Notes
- https://github.com/argoproj/argo-workflows/releases/tag/v4.0.5Release Notes
- https://github.com/argoproj/argo-workflows/security/advisories/GHSA-jcc8-g2q4-9fxqExploit, Vendor Advisory
- https://access.redhat.com/security/cve/CVE-2026-42294
- https://bugzilla.redhat.com/show_bug.cgi?id=2468443
- https://github.com/argoproj/argo-workflows/security/advisories/GHSA-jcc8-g2q4-9fxqExploit, Vendor Advisory
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-42294.json
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.