Omni has a TOCTOU race condition that allows multiple concurrent uses of a single-use SAML session token

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

7.0 · CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H

EPSS

• CVE-2026-45720: 0.14% estimated exploitation activity in the next 30 days; percentile 3.62 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary SAML.getSession (internal/pkg/auth/interceptor/saml.go) checks the Used flag on a SAMLAssertion resource and then marks it used in two separate state operations. Because the check and the update are not atomic, concurrent requests carrying the same saml-session token can both observe Used == false, both pass validation, and both return a successful authentication context. An attacker who obtains a valid saml-session token can exploit this window to authenticate as the token's owner multiple times, defeating the one-time-use guarantee. Severity - Attack Vector: Local: the attacker needs to either be able to intercept the local, unencrypted traffic or needs access to user's browser. - Attack Complexity: High: the attacker must first obtain a valid saml-session token belonging to the victim (requires a separate interception step; the token is ephemeral and single-use by design). - Privileges Required: None: no Omni account is required to carry out the race once the session token…

Published by the source

5 Jun 2026, 15:25 UTC

Last modified by the source

5 Jun 2026, 15:25 UTC

Source last checked

26 Oct 2026, 15:23 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-5x9f-6vg5-qg4m

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# Patch Next advisory brief: CVE-2026-45720

Advisory: Omni has a TOCTOU race condition that allows multiple concurrent uses of a single-use SAML session token
IDs: CVE-2026-45720, GHSA-5x9f-6vg5-qg4m
Record: https://patchnext.com/advisories/cve-2026-45720 (revision 1, source checked 26 Oct 2026, 15:23 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.0)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: github.com/siderolabs/omni 1.7.3, 1.6.6. A vendor fix does not mean a deployment is fixed.

## Affected components
- Go github.com/siderolabs/omni: affected < 1.6.6; >= 1.7.0, < 1.7.3; fixed in 1.6.6, 1.7.3

## Suggested inspection (read-only)
- Go github.com/siderolabs/omni: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on github.com/siderolabs/omni.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-5x9f-6vg5-qg4m (GitHub-reviewed advisory GHSA-5x9f-6vg5-qg4m lists affected ranges: Go github.com/siderolabs/omni >=0 =1.7.0 <1.7.3)

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