CVE-2026-48503: high-severity vulnerability in mz-automation libiec61850
libIEC61850: Remote information disclosure in MMS file service via out-of-range initialPosition in fileOpen followed by fileRead
Published
E-mail alert when it lands in KEV, gets a public PoC or its score goes up.
21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 7.5epss 0.5%
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.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Affected products
mz-automation · libiec61850Related CVEs — mz-automation libiec61850
In the same product, most dangerous first.
CVE-2020-15158HIGHHeap buffer overflow in libIEC61850EPSS 2.0%CVE-2019-1010300—CVE-2019-1010300EPSS 1.3%CVE-2026-18583MEDIUMmz-automation libiec61850 MMS Request mms_mapping.c checkDataSetAccess out-of-boundsEPSS 0.9%CVE-2026-18582MEDIUMmz-automation libiec61850 Report Sending Path reporting.c Reporting_RCBWriteAccessHandler free of memory not on the heapEPSS 0.9%CVE-2026-48741HIGHlibIEC61850: Remote NULL dereference in MMS Read alternate-access sub-array path leads to server-side DoSEPSS 0.5%CVE-2026-68906HIGHlibIEC61850: Infinite loop and out-of-bounds read in ACSE parseUserInformation when parsing a malformed AARE PDUEPSS 0.5%