libIEC61850: Remote information disclosure in MMS file service via out-of-range initialPosition in fileOpen followed by fileRead
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, the MMS file service in src/mms/iso_mms/server/mms_file_service.c accepts an out-of-range initialPosition in fileOpen and stores it in the file-read state. The fileRead path then subtracts the larger read position from the file size using unsigned arithmetic and fails to limit the response to the actual FileSystem_readFile return value. The oversized response can include stale bytes from the reused connection buffer after the requested file contents, disclosing prior response data and protocol fragments to an unauthenticated remote client when the file service is enabled. This issue is fixed in version 1.6.2.
CVE-2026-48503
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-48503
libiec61850
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"vendor": "mz-automation",
"product": "libiec61850",
"versions": [
{
"status": "affected",
"version": "< 1.6.2"
}
]
}
]- Related CVEs
- CVE-2026-48503
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #32752 · Revision 1
- Added to Heist Feed
- Publisher date