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TI-2026-49923 Aliases CVE-2026-71254GHSA-29rm-wvww-5gjv

nanoMODBUS Server-Side Out-of-Bounds Write in handle_read_file_record()

Priority MEDIUM 50CWE-787Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
No fix listed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-787 and the CVSS impact.

Summary

nanoMODBUS through v1.23.0 contains an out-of-bounds write in the Modbus server-side handle_read_file_record function (FC 0x14, Read File Record) in nanomodbus.c. The function validates that the total request size does not exceed 245 bytes and that each sub-request's record_length is at most 124, but it never validates the CUMULATIVE response size across all sub-requests before processing them.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00553 46th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
debevvnanoMODBUSup to 1.23.0—No fix listedCNA
  • nanoMODBUS Vendordebevv Affected up to 1.23.0 Fixed in — No fix listed CNA

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-71254
  2. 2026-10-03 Alias added: GHSA-29rm-wvww-5gjv

References

Advisory 2

  • TI-2026-49925 nanoMODBUS Client-Side Out-of-Bounds Read Leading to Wild-Pointer Write via object_id CVSS 3.1CRITICAL 9.8
  • TI-2026-49924 nanoMODBUS Client-Side Out-of-Bounds Write via object_length in recv_read_device_identification_res() CVSS 3.1HIGH 8.6
  • TI-2026-39286 nanoMODBUS Off-by-One Buffer Overflow in recv_msg_header() via Crafted MBAP Length Field CVSS 4.0HIGH 7.8

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences