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CVE-2026-35383 Bentley Systems CVE debrief

Bentley Systems iTwin Platform exposed a Cesium ion access token in the source of some web pages. An unauthenticated attacker could use this token to enumerate or delete certain assets. As of 2026-03-27, the token is no longer present in the web pages and cannot be used to enumerate or delete assets. The vulnerability has been mitigated, and no further action is required from users. The incident highlights the importance of secure coding practices and access token management.

Vendor
Bentley Systems
Product
iTwin Platform
CVSS
MEDIUM 6.5
CISA KEV
Not listed in stored evidence
Original CVE published
2026-04-02
Original CVE updated
2026-04-02
Advisory published
2026-04-02
Advisory updated
2026-04-02

Who should care

Security teams and administrators responsible for Bentley Systems iTwin Platform should review and verify that their instances are not affected by this vulnerability. Although the token has been removed, it's essential to ensure that similar issues do not exist in the platform's code. Additionally, developers working with access tokens and sensitive data should be aware of the risks associated with exposing such tokens.

Technical summary

The vulnerability involves an exposed Cesium ion access token in the source code of some web pages in Bentley Systems iTwin Platform. This token could be used by an unauthenticated attacker to enumerate or delete certain assets. The token was removed as of 2026-03-27, and the vulnerability has been mitigated. The incident demonstrates the importance of secure coding practices, access token management, and regular code reviews.

Defensive priority

Medium priority should be given to reviewing and verifying that Bentley Systems iTwin Platform instances are not affected by this vulnerability. Although the token has been removed, it's essential to ensure that similar issues do not exist in the platform's code.

Recommended defensive actions

  • Review and verify that Bentley Systems iTwin Platform instances are not affected by this vulnerability.
  • Ensure that similar issues do not exist in the platform's code by performing regular code reviews.
  • Develop and implement secure coding practices for access token management.
  • Monitor the platform for any potential security issues related to access tokens.
  • Update incident response plans to include procedures for handling exposed access tokens.

Evidence notes

The source item provided by CISA contains detailed information about the vulnerability, including a description of the issue, affected products, and mitigation details. The CVE record and NVD detail provide additional context and information about the vulnerability.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-35383 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-35383

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

  • CVE-2026-35383 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-35383

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

Supplemental references

  • Source item URL

    Unverified legacy reference

    URL: https://raw.githubusercontent.com/cisagov/CSAF/develop/csaf_files/IT/white/2026/va-26-092-01.json

    cisa_csaf

  • Source reference

    Unverified legacy reference

    URL: https://cesium.com/learn/ion/cesium-ion-access-tokens/

    Reference

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.