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PatchSiren cyber security CVE debrief

CVE-2026-15615 Logto CVE debrief

CVE-2026-15615 is a HIGH-severity vulnerability in Logto, a service that provides authentication and authorization solutions. The issue arises from the omission of validation for the SAML <Conditions> element, which allows attackers to manipulate time and audience restrictions, potentially leading to indefinite replay of assertions. This vulnerability could allow attackers to bypass security measures by replaying assertions without proper time and audience restrictions. Users of Logto, especially those relying on SAML for authentication, should be aware of this vulnerability and review configurations to ensure proper validation of SAML <Conditions> elements.

Vendor
Logto
Product
Unknown
CVSS
HIGH 7.5
CISA KEV
Not listed in stored evidence
Original CVE published
2026-07-23
Original CVE updated
2026-07-27
Advisory published
2026-07-23
Advisory updated
2026-07-27

Who should care

Users of Logto, especially those relying on SAML for authentication, should be aware of this vulnerability. It could allow attackers to bypass security measures by replaying assertions without proper time and audience restrictions. Affected operators, platforms, vulnerability-management, and security teams should review configurations and implement additional security measures.

Technical summary

The vulnerability is caused by the lack of validation for the SAML <Conditions> element in Logto. This element is crucial for specifying time and audience restrictions on assertions. Without proper validation, an attacker could modify these conditions, allowing for the indefinite replay of assertions. This could lead to unauthorized access or other security breaches. Affected product deployments should be identified, and owners assigned for follow-up. Review of compensating controls for exposed systems is recommended while remediation is scheduled and verified.

Defensive priority

High

Recommended defensive actions

  • Review and update Logto configurations to ensure proper validation of SAML <Conditions> elements.
  • Implement additional monitoring to detect potential replay attacks.
  • Consider compensating controls, such as additional authentication factors, to mitigate the risk.
  • Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up.
  • Review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance.
  • Plan vendor-supported updates or mitigations through normal change control where exposure is confirmed.
  • Check relevant monitoring, detection, and logs for exposed assets that need extra review.

Evidence notes

The CVE record and NVD detail provide information on the vulnerability. However, the exact scope of affected systems and the vendor's remediation plan are not specified in the provided data. Further verification is needed to understand the full impact and to confirm affected deployments. Defenders should review the official advisory and CVE record for validation of affected scope, severity, and vendor guidance.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-15615 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-15615

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-15615 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-15615

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

  • Source reference

    Unverified legacy reference

    URL: https://github.com/logto-io/logto/blob/ea3ede35028dfd0bbb6d7b239623ce0e7f6cdff8/packages/connectors/connector-saml/src/utils.ts

    [email protected]

  • Source reference

    Unverified legacy reference

    URL: https://github.com/logto-io/logto/blob/ea3ede35028dfd0bbb6d7b239623ce0e7f6cdff8/packages/core/src/sso/SamlConnector/utils.ts

    [email protected]

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.