CVE-2026-111880: FreeRDP 2.0.0 before 3.32.0 Heap Out-of-Bounds Write via NTLM MIC Offset

Severity: high (CVSS 7.4 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-10-17 · updated 2026-10-19
Weakness: CWE-787

Description

FreeRDP versions from 2.0.0 before 3.32.0 contain a heap out-of-bounds write in the server hash-callback NTLM path that fails to validate the MIC offset. Unauthenticated attackers can send a crafted AUTHENTICATE_MESSAGE with a backward session-key offset and MIC offset to write 16 zero bytes beyond the allocation.

Affected products

FreeRDP: from 2.0.0 before 3.32.0 — fixed in 3.32.0

How to fix

Upgrade to a fixed version: FreeRDP 3.32.0. Check the vendor advisory for mitigations.

References

https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-cmgx-558f-vh67
https://www.vulncheck.com/advisories/freerdp-2.0.0-before-3.32.0-heap-out-of-bounds-write-via-ntlm-mic-offset

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