Cyber Resilience

CVE-2025-27809

MediumUpdated

Published: 25 March 2025

Published
25 March 2025
Modified
05 June 2026
KEV Added
Patch
CVSS Score v3.1 5.4 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N
EPSS Score 0.0014 34.0th percentile
Risk Priority 11 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2025-27809 is a medium-severity Initialization of a Resource with an Insecure Default (CWE-1188) vulnerability in Arm Mbed Tls. Its CVSS base score is 5.4 (Medium).

Operationally, ranked at the 34.0th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

Mbed TLS before 2.28.10 and 3.x before 3.6.3, on the client side, accepts servers that have trusted certificates for arbitrary hostnames unless the TLS client application calls mbedtls_ssl_set_hostname.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

arm
mbed tls
≤ 2.28.10
trustedfirmware
mbed tls
3.0.0 — 3.6.3

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-1188

Requires documented secure initialization practices and avoidance of insecure defaults in configuration baselines.

addresses: CWE-1188

Reviewing and updating baseline when components are installed or upgraded prevents initialization with insecure defaults.

addresses: CWE-1188

Requiring explicit configuration to minimal functionality overrides insecure defaults that would otherwise enable excess capabilities.

addresses: CWE-1188

Tailoring replaces or augments insecure default initializations with system-specific values and compensating controls before deployment.

addresses: CWE-1188

Central configuration overrides or replaces insecure default initializations that would otherwise be left unchanged on each system.

addresses: CWE-1188

SCRM practices during acquisition and configuration management address insecure default initializations shipped by vendors.

addresses: CWE-1188

Scans detect resources initialized with insecure defaults that create exploitable conditions.

addresses: CWE-1188

Instruction on secure initialization of security controls prevents leaving resources with insecure defaults after installation.

References