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PatchSiren cyber security CVE debrief

CVE-2026-3303 IBM CVE debrief

IBM Concert 1.0 through 3.0.0 uses cross-origin resource sharing (CORS) which could allow an attacker to carry out privileged actions as the domain name is not being limited to only trusted domains. This low-severity vulnerability allows attackers to carry out privileged actions due to improper CORS configuration. Defenders responsible for IBM Concert instances, especially those exposed to untrusted domains, should assess exposure and prioritize verification of CORS configuration. The CVE record and NVD entry provide limited information about the vulnerability, and further verification of affected versions and remediation is required.

Vendor
IBM
Product
Concert
CVSS
LOW 3.7
CISA KEV
Not listed in stored evidence
Original CVE published
2026-10-19
Original CVE updated
2026-10-20
Advisory published
2026-10-19
Advisory updated
2026-10-20

Who should care

Defenders responsible for IBM Concert instances, especially those exposed to untrusted domains, should assess exposure and prioritize verification of CORS configuration.

Why it matters

CVE-2026-3303 is a low-severity vulnerability in IBM Concert that allows an attacker to carry out privileged actions due to improper CORS configuration. Defenders should assess exposure and prioritize verification of CORS configuration for IBM Concert instances, especially those exposed to untrusted domains. The CVE record and NVD entry provide limited information about the vulnerability, and further verification of affected versions and remediation is required.

  • Defenders need to verify CORS configuration to prevent unauthorized actions.
  • Exposure to untrusted domains may allow attackers to carry out privileged actions.

Technical summary

IBM Concert 1.0 through 3.0.0 uses cross-origin resource sharing (CORS) which could allow an attacker to carry out privileged actions as the domain name is not being limited to only trusted domains. This vulnerability allows attackers to carry out privileged actions due to improper CORS configuration. Defenders should assess exposure and prioritize verification of CORS configuration for IBM Concert instances, especially those exposed to untrusted domains.

Defensive priority

Defenders should assess exposure and prioritize verification of CORS configuration for IBM Concert instances, especially those exposed to untrusted domains.

Recommended defensive actions

  • Verify CORS configuration for IBM Concert instances
  • Assess exposure to untrusted domains
  • Prioritize verification of affected versions

Evidence notes

The CVE record and NVD entry provide limited information about the vulnerability. Further verification of affected versions and remediation is required.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-3303 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-3303

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

  • CVE-2026-3303 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-3303

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

Supplemental references

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.