Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HSummary
CVE-2026-34875 is a critical-severity Classic Buffer Overflow (CWE-120) vulnerability in Trustedfirmware Mbed Tls. Its CVSS base score is 9.8 (Critical).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 30th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SI-10 (Information Input Validation) — 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-2026-34875 is a buffer overflow vulnerability (CWE-120) discovered in Mbed TLS versions through 3.6.5 and TF-PSA-Crypto 1.0.0. The issue arises during public key export for FFDH (Finite Field Diffie-Hellman) keys, where insufficient bounds checking can lead to a buffer overflow. It has been assigned a CVSS v3.1 base score of 9.8 (Critical), reflecting network accessibility (AV:N), low attack complexity (AC:L), no privileges required (PR:N), no user interaction needed (UI:N), and unchanged scope (S:U) with high impacts on confidentiality, integrity, and availability (C:H/I:H/A:H).
Unauthenticated remote attackers can exploit this vulnerability over the network without user interaction. Successful exploitation could allow arbitrary code execution, data corruption, or denial of service, depending on the context in which the affected components are deployed, such as in TLS/SSL implementations or cryptographic libraries used in embedded systems, servers, or IoT devices.
Mitigation details are provided in the official Mbed TLS security advisories, available at https://mbed-tls.readthedocs.io/en/latest/security-advisories/ and specifically https://mbed-tls.readthedocs.io/en/latest/security-advisories/mbedtls-security-advisory-2026-03-ffdh-buffer-overflow/. Security practitioners should consult these for patch availability, upgrade instructions, and workarounds for vulnerable versions.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-17993
Vulnerability Data
An issue was discovered in Mbed TLS through 3.6.5 and TF-PSA-Crypto 1.0.0. A buffer overflow can occur in public key export for FFDH keys.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
—
—
—
V5.2.1
Mitigating Controls (NIST 800-53 r5) AI
Developer testing and analysis can find missing size checks before deployment.
Input validation directly enforces size checks before buffer copies.
Engineering principles require bounds checking and safe buffer handling in design.
Memory protection limits the impact of an overflow once it occurs.
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 development practices directly enforce bounds checking and input validation that prevent classic buffer overflows.
Vulnerability identification processes such as code review or scanning detect classic buffer overflows before exploitation.
Routine patching replaces vulnerable code containing unchecked buffer copies with corrected versions.
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.
Secure coding directly requires bounds-checked memory operations, addressing the root cause of CWE-120.
Security testing in development and acceptance can detect buffer overflows through fuzzing and static analysis, though it does not prevent them at the source.
Secure development life cycle mandates processes that can include input validation and bounds checking to prevent buffer overflows.
Application security requirements can specify input-size validation and safe buffer handling to mitigate classic buffer overflows.
Secure system architecture and engineering principles promote defensive coding patterns that reduce the likelihood of unchecked buffer copies.