Cyber Resilience

CVE-2025-49087

Trustedfirmware Mbed Tls 3.6.1 – 3.6.4

Public PoC
Published
20 July 2025
Modified
17 June 2026
Patch / advisory
CVSS Score v3.1 4.0
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:N/A:N
EPSS Score 0.0040 33th percentile
Risk Priority 34 floored blend · peak EPSS

Summary

CVE-2025-49087 is a medium-severity Covert Timing Channel (CWE-385) vulnerability in Trustedfirmware Mbed Tls. Its CVSS base score is 4.0 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Data Obfuscation (T1001); ranked at the 33th 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 SC-31 (Covert Channel Analysis) — see the control section below for these in your framework.

EU & UK References

Vulnerability Data

In Mbed TLS 3.6.1 through 3.6.3 before 3.6.4, a timing discrepancy in block cipher padding removal allows an attacker to recover the plaintext when PKCS#7 padding mode is used.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1001 Data Obfuscation Command And Control
Adversaries may obfuscate command and control traffic to make it more difficult to detect.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2024-28755Same product: Trustedfirmware Mbed Tls
CVE-2024-23744Same product: Trustedfirmware Mbed Tls
CVE-2026-34876Same product: Trustedfirmware Mbed Tls
CVE-2026-25833Same product: Trustedfirmware Mbed Tls
CVE-2024-45157Same product: Trustedfirmware Mbed Tls
CVE-2023-45199Same product: Trustedfirmware Mbed Tls
CVE-2025-49601Same product: Trustedfirmware Mbed Tls
CVE-2026-34873Same product: Trustedfirmware Mbed Tls
CVE-2026-34874Same product: Trustedfirmware Mbed Tls
CVE-2024-45159Same product: Trustedfirmware Mbed Tls

Affected Assets

trustedfirmware
mbed tls
3.6.1 — 3.6.4

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

Covert channel analysis directly identifies timing channels that could leak information.

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.

PR.PS-06 mostly match
prevents

Secure development practices (reviews, testing) directly reduce introduction of timing-channel vulnerabilities in code.

DE.CM-09 partial match
prevents

Runtime monitoring of hardware/software behavior can detect anomalous timing patterns that indicate covert channels.

ID.RA-01 partial match
prevents

Vulnerability identification processes can surface timing-channel weaknesses during design or code analysis.

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.

A.8.15 Logging partial match
degrades

Detailed logging can reveal timing anomalies but does not prevent covert timing channels.

finds

Continuous monitoring may detect timing-based exfiltration but does not eliminate the channel itself.

mitigates

Network segmentation reduces attack surface but does not address intra-process timing channels.

mitigates

Network segregation limits external timing observation but not internal covert timing.

prevents

Secure architecture principles can include timing-channel countermeasures but are not specific.

prevents

Secure coding guidelines may recommend constant-time algorithms but coverage is not guaranteed.

References