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PatchSiren cyber security CVE debrief

CVE-2026-90782 Systerel CVE debrief

CVE-2026-90782 is a null pointer dereference vulnerability in S2OPC through 1.7.3. The vulnerability occurs in the msg_subscription_publish_bs__alloc_notification_message_items() function where a failed allocation for DataChangeNotification is overwritten by a successful allocation for EventNotificationList. This can be triggered by attackers causing heap allocation failures on sessions with both data-change and event notifications, potentially leading to server process termination.

Vendor
Systerel
Product
S2OPC
CVSS
MEDIUM 6
CISA KEV
Not listed in stored evidence
Original CVE published
2026-09-13
Original CVE updated
2026-09-23
Advisory published
2026-09-13
Advisory updated
2026-09-23

Who should care

Defenders responsible for S2OPC deployments, especially those with both data-change and event notifications enabled, should assess exposure and prioritize verification and potential updates or compensating controls.

Why it matters

CVE-2026-90782 is a null pointer dereference vulnerability in S2OPC through 1.7.3 that can be triggered by attackers causing heap allocation failures, potentially leading to server process termination. Defenders should prioritize verifying exposure, especially in deployments with both data-change and event notifications enabled, and assess the need for updates or compensating controls.

  • Potential server process termination due to heap allocation failures
  • Need for verification of exposure in S2OPC deployments
  • Potential need for updates or compensating controls
  • Importance of monitoring for potential exploitation attempts

Technical summary

The vulnerability occurs in the msg_subscription_publish_bs__alloc_notification_message_items() function of S2OPC through 1.7.3. A failed allocation for DataChangeNotification is overwritten by a successful allocation for EventNotificationList, allowing attackers to trigger heap allocation failures on sessions with both data-change and event notifications, potentially causing server process termination.

Defensive priority

Defenders should prioritize verifying exposure in S2OPC deployments, especially those with both data-change and event notifications enabled, and assess the need for updates or compensating controls.

Recommended defensive actions

  • Verify S2OPC version and assess exposure
  • Review and update S2OPC to a fixed version if available
  • Implement compensating controls for sessions with data-change and event notifications
  • Monitor for potential exploitation attempts
  • Perform asset inventory of S2OPC deployments
  • Review rollback and change window procedures for S2OPC updates
  • Track source code changes for S2OPC vulnerability fixes

Evidence notes

The vulnerability details are based on the CVE Program record and the NVD vulnerability detail page. Additional information is available from various source references, including GitLab repositories and Vulncheck advisories.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-90782 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-90782

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

  • CVE-2026-90782 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-90782

    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.