What’s Vulnerable › Vulnerabilities

CVE-2026-45720: Omni: TOCTOU race condition allows multiple concurrent uses of a single-use SAML session token

• Severity: high (CVSS 7.0 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.1% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-09-17 · updated 2026-09-24
• Weakness: CWE-294

Description

Omni manages Kubernetes on bare metal, virtual machines, or in a cloud. Prior to 1.6.6 and from 1.7.0 until 1.7.3, SAML.getSession in internal/pkg/auth/interceptor/saml.go checks SAMLAssertion.Used and marks it used in separate state operations. Concurrent requests carrying the same captured saml-session token can each observe the assertion as unused and obtain authentication as the victim before either update is visible. The attacker can invoke SAML-protected gRPC endpoints, use ConfirmPublicKey to create multiple persistent credentials tied to the victim, and generate audit entries attributed to the victim, with the resulting access potentially affecting confidentiality, integrity, and availability according to the victim's privileges. This issue is fixed in versions 1.6.6 and 1.7.3.

Affected products

• siderolabs omni: before 1.6.6; from 1.7.0, < 1.7.3

References

• https://github.com/siderolabs/omni/commit/272d3f4dd00e778b39fde09afde35575fe13ef13
• https://github.com/siderolabs/omni/commit/4c4c1e2d8226914f26774a309a91595f168ee921
• https://github.com/siderolabs/omni/commit/ced79da6c032d2103803eb53343d0916cc957d2a
• https://github.com/siderolabs/omni/pull/2816
• https://github.com/siderolabs/omni/releases/tag/v1.6.6
• https://github.com/siderolabs/omni/releases/tag/v1.7.3
• https://github.com/siderolabs/omni/security/advisories/GHSA-5x9f-6vg5-qg4m

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