CVE-2026-78049Public exploitNetwork attack vector

Remote server crash via undersized NodeAttributes cast

Published Aug 22, 2026 · Updated Aug 22, 2026

Out-of-bounds read in Systerel S2OPC 1.7.0 through 1.7.3 allows remote attackers to crash OPC UA servers via AddNodes requests. The AddNodes path passes a generic NodeAttributes buffer as a larger VariableAttributes, ObjectAttributes, or MethodAttributes structure, so later field reads exceed the supplied allocation. Reachability requires the nondefault S2OPC_NODE_MANAGEMENT build option and a crafted AddNodes request; no authentication or user interaction is required, and impact is limited to a server crash.

CVSS severityUnavailable
Unscored
EPSS probability0.40%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds read in Systerel S2OPC 1.7.0 through 1.7.3 allows remote attackers to crash OPC UA servers via AddNodes requests. The AddNodes path passes a generic NodeAttributes buffer as a larger VariableAttributes, ObjectAttributes, or MethodAttributes structure, so later field reads exceed the supplied allocation. Reachability requires the nondefault S2OPC_NODE_MANAGEMENT build option and a crafted AddNodes request; no authentication or user interaction is required, and impact is limited to a server crash.

The record

CVE
CVE-2026-78049
Published
Aug 22, 2026
Updated
Aug 22, 2026
Vendor
Systerel
Product
S2OPC
Classifications
CWE-119, CWE-125, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 22, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 22, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=1.7.0
  2. Affected versionversion=1.7.1
  3. Affected versionversion=1.7.2
  4. Affected versionversion=1.7.3

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Systerel · S2OPCversion=1.7.0; version=1.7.1; version=1.7.2; version=1.7.3

Published CVSS scores

3.7VulDBCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L/E:P/RL:O/RC:C
2.6VulDBAV:N/AC:H/Au:N/C:N/I:N/A:P/E:POC/RL:OF/RC:C
6.3VulDBCVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:P
3.7VulDBCVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L/E:P/RL:O/RC:C

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-119Memory Corruption
CWE-125Out-of-Bounds Read
T1499Endpoint Denial of Service

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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