CVE-2025-47917Network attack vector

Code execution via undocumented deep-free of head list

Published Jul 20, 2025 · Updated Nov 3, 2025

Use-after-free in Mbed TLS before 3.6.4 allows attackers to execute arbitrary code through applications that pass a non-NULL name list. mbedtls_x509_string_to_names() deep-frees the caller-supplied head list although its output-only contract leaves callers retaining pointers to that memory. Exposure requires a direct call with a non-NULL head; internal calls are unaffected, while double-free or later reuse can corrupt memory.

CVSS severity8.9
High
EPSS probability2.06%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in Mbed TLS before 3.6.4 allows attackers to execute arbitrary code through applications that pass a non-NULL name list. mbedtls_x509_string_to_names() deep-frees the caller-supplied head list although its output-only contract leaves callers retaining pointers to that memory. Exposure requires a direct call with a non-NULL head; internal calls are unaffected, while double-free or later reuse can corrupt memory.

The record

CVE
CVE-2025-47917
Published
Jul 20, 2025
Updated
Nov 3, 2025
Vendor
TrustedFirmware.org
Product
Mbed TLS
Classifications
CWE-416
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 20, 2025CVE publishedPublication date reported by the CVE source.
  2. Nov 3, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <3.6.4

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

TrustedFirmware.org · Mbed TLSversion=0 <3.6.4

Published CVSS scores

8.9MITRECVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-416Use After Free

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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