libIEC61850: Remote NULL dereference in MMS Read alternate-access sub-array path leads to server-side DoS
CVE-2026-48741 · published 16 Oct 2026
How serious is it
- Severity: high, CVSS score 7.5 out of 10.
- No exploit prediction (EPSS) score yet.
- Not on the CISA list of exploited vulnerabilities.
- No public exploit in Exploit-DB.
Is your app affected by CVE-2026-48741?
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Who is affected
- mz-automation libiec61850: < 1.6.2
How to check
- Find out whether you run the affected product and which version, then compare it with the versions above.
How to fix
Copies a prompt for Claude Code, Cursor or Codex that asks it to check whether you run this product.
- Apply the vendor's update or mitigation from the references below. If there is none yet, limit exposure of the affected service until there is.
- If a vulnerable version was live, check your logs and rotate the secrets that server could read.
The advisory
libIEC61850 is an open-source implementation of IEC 61850 client and server protocols including MMS, GOOSE, Sampled Values, and R-Session. Prior to 1.6.2, alternateArrayAccess in src/mms/iso_mms/server/mms_read_service.c does not validate an alternate-access sub-array range when numberOfElements is greater than zero. An out-of-range MmsValue_getElement call returns NULL, and the sub-array branch passes that value to MmsValue_isDeletable, causing a NULL pointer dereference. A remote MMS Read request can therefore crash servers whose data models contain arrays, while the single-element error path handles the same invalid index safely. This issue is fixed in version 1.6.2.
Check your whole app
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References
- github.com/mz-automation/libiec61850/security/advisories/GHSA-8mfr-hq64-9w33
- github.com/mz-automation/libiec61850/commit/7c15310405def00cac628ebde4ce1404bfb8a411
- github.com/mz-automation/libiec61850/releases/tag/v1.6.2
Merged from CVE List. Last updated 24 Oct 2026. All vulnerabilities · RSS · JSON