Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:LSummary
CVE-2026-27951 is a medium-severity Integer Overflow or Wraparound (CWE-190) vulnerability in Freerdp Freerdp. Its CVSS base score is 5.3 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 27th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SA-8 (Security and Privacy Engineering Principles) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2026-27951 is a vulnerability in FreeRDP, a free implementation of the Remote Desktop Protocol, affecting versions prior to 3.23.0. The issue lies in the Stream_EnsureCapacity function, which can enter an endless blocking loop due to an integer overflow or wraparound (CWE-190). This flaw impacts all client and server implementations that incorporate FreeRDP.
A remote attacker requires no privileges or user interaction and can exploit the vulnerability over the network with low attack complexity, as reflected in its CVSS v3.1 base score of 5.3 (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L). Exploitation causes a denial of service through the blocking loop, but is practically limited to 32-bit systems where available physical memory is greater than or equal to SIZE_MAX.
FreeRDP version 3.23.0 includes a patch addressing the vulnerability, with no known workarounds available. Mitigation details are documented in the GitHub security advisory at GHSA-qcfc-ghxr-h927 and the fixing commit at 118afc0b954ba9d5632b7836ad24e454555ed113.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-8755
Vulnerability Data
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.23.0, the function `Stream_EnsureCapacity` can create an endless blocking loop. This may affect all client and server implementations using `FreeRDP`. For practical exploitation this will only work…
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on 32bit systems where the available physical memory is `>= SIZE_MAX`. Version 3.23.0 contains a patch. No known workarounds are available.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V5.2.6
Mitigating Controls (NIST 800-53 r5) AI
Developer testing and evaluation (static analysis, fuzzing, unit tests) directly finds integer overflow defects before deployment.
Secure engineering principles require use of safe arithmetic constructs or language features that structurally eliminate integer overflow during calculation.
Input validation enforces bounds on values before arithmetic, stopping the conditions that trigger overflow or wraparound.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure SDLC practices directly require use of safe arithmetic, bounds checks, and testing that prevent integer overflows.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Security testing in development can detect integer overflows before release.
Secure SDLC mandates input validation and arithmetic checks that prevent integer overflows.
Application security requirements include bounds checking and safe arithmetic to avoid overflow conditions.
Secure architecture principles require defensive coding patterns that mitigate integer wraparound risks.
Secure coding standards explicitly forbid unsafe integer operations and mandate overflow-safe constructs.