# CVE-2026-45720: Sidero Labs Omni TOCTOU race condition in SAML session token handling

Source: https://junglewise.ai/threats/cve-2026-45720-sidero-labs-omni-toctou-race-condition-in-saml-session-token  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-17. Updated: 2026-06-05  
License: CC BY 4.0 with a link back

CVE-2026-45720 · Severity: high · CVSS 7 · Published 2026-09-17

Sidero Labs Omni, a platform for managing Kubernetes clusters, contains a flaw in how it handles login security tokens. An attacker who intercepts a user's temporary login token can use a high-speed 'race condition' to reuse that token multiple times before the system marks it as expired. This could allow an attacker to impersonate a legitimate user, gain unauthorized access to sensitive data, or establish permanent backdoors into the system.

Technologies: [github.com/siderolabs/omni (Go)](https://junglewise.ai/threats/technologies/github-com-siderolabs-omni), [Sidero Labs Omni](https://junglewise.ai/threats/technologies/omni). Vendors: [Go](https://junglewise.ai/threats/vendors/go), [Sidero Labs](https://junglewise.ai/threats/vendors/sidero-labs).

## Quick answers

**Is CVE-2026-45720 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-45720 being exploited in the wild.

**How severe is CVE-2026-45720?** High severity, with a CVSS score of 7, published 17 September 2026.

**Which products and versions are affected?** github.com/siderolabs/omni (Go) SEMVER:introduced=0,fixed=1.6.6, SEMVER:introduced=0,fixed=1.6.6,introduced=1.7.0,fixed=1.7.3; Sidero Labs Omni < 1.6.6, >= 1.7.0, < 1.7.3.

**Is there a fix for CVE-2026-45720?** Yes. github.com/siderolabs/omni (Go): upgrade to 1.6.6, 1.7.3 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-45720 attacked?** It is attacked with local access, in a hosted service.

**Am I affected by CVE-2026-45720?** Check whether you run github.com/siderolabs/omni (Go) or Sidero Labs Omni at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- github.com/siderolabs/omni (Go): upgrade to 1.6.6, 1.7.3 or later

  ```sh
  go get github.com/siderolabs/omni@v1.7.3
  ```


## Technical details

A Time-of-Check Time-of-Use (TOCTOU) race condition exists in the `SAML.getSession` function within `internal/pkg/auth/interceptor/saml.go`. The component checks the `Used` flag on a `SAMLAssertion` and subsequently updates it in non-atomic state operations. By sending concurrent requests using the same `saml-session` token, an attacker can bypass the one-time-use restriction. This allows for session replay, enabling the attacker to authenticate as the victim and potentially confirm multiple attacker-controlled public keys to establish persistent access. Exploitation requires the attacker to intercept ephemeral, unencrypted local traffic or have access to the victim's browser during a SAML authentication flow.

## Affected products

- Sidero Labs Omni < 1.6.6, >= 1.7.0, < 1.7.3

## Identifiers

- CVE-2026-45720
- GHSA-5x9f-6vg5-qg4m
- GO-2026-5160

## Timeline

- 2026-06-05: disclosed
- 2026-06-05: advisory
- 2026-06-05: patched: Patched in versions 1.6.6 and 1.7.3

## References

- [https://api.github.com/users/bugbunny-research](https://api.github.com/users/bugbunny-research)
- [https://github.com/bugbunny-research](https://github.com/bugbunny-research)
- [https://api.github.com/users/bugbunny-research/gists%7B/gist_id%7D](https://api.github.com/users/bugbunny-research/gists%7B/gist_id%7D)
- [https://api.github.com/users/bugbunny-research/repos](https://api.github.com/users/bugbunny-research/repos)
- [https://avatars.githubusercontent.com/u/262839898?v=4](https://avatars.githubusercontent.com/u/262839898?v=4)
- [https://api.github.com/users/bugbunny-research/events%7B/privacy%7D](https://api.github.com/users/bugbunny-research/events%7B/privacy%7D)

## Related threats

- [Sidero Labs Omni information disclosure in ResourceService](https://junglewise.ai/threats/cve-2026-45726-sidero-labs-omni-information-disclosure-in-resourceservice)
- [Sidero Labs Omni path traversal in CreateSchematic API](https://junglewise.ai/threats/cve-2026-45723-sidero-labs-omni-path-traversal-in-createschematic-api)
- [GO-2025-3979 - Omni Wireguard SideroLink potential escape in github.com/siderolabs/omni](https://junglewise.ai/threats/cve-2025-59824-omni-wireguard-siderolink-potential-escape)
- [GO-2025-4022 - Omni vulnerable to information leak via API in github.com/siderolabs/omni](https://junglewise.ai/threats/cve-2025-61688-omni-vulnerable-to-information-leak-via-api)
- [GO-2025-4021 - Omni is Vulnerable to DoS via Empty Create/Update Resource Requests in github.com/siderolabs/omni](https://junglewise.ai/threats/cve-2025-59836-omni-is-vulnerable-to-dos-via-empty-create-update-resource)