Vulnerability · Published Oct 16, 2026 · Assigned by GitHub_M
CVE-2026-68906libIEC61850: Infinite loop and out-of-bounds read in ACSE parseUserInformation when parsing a malformed AARE PDU
High 8.7
In plain English
A high-severity out-of-bounds read in libiec61850 from mz-automation. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 41% of all known vulnerabilities).
Official description
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, parseUserInformation in src/mms/iso_acse/acse.c checks len for zero before validating the negative bufPos returned by BerDecoder_decodeLength for a truncated long-form length. The continue path therefore swallows the error, reads buffer[-1], resets parsing to the beginning, and repeats the same malformed state. An unauthenticated remote peer can send a malformed AARE PDU during association to cause an infinite CPU loop under a normal allocator or a one-byte out-of-bounds read and process abort when the preceding byte is inaccessible. This issue is fixed in version 1.6.2.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| mz-automation | libiec61850 | < 1.6.2 |
Weakness: CWE-125, CWE-835 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N